The First Triumvirate of 60 BC: HSC Ancient History

Syllabus dot point

“The formation of the First Triumvirate in 60 BC as a private compact between Caesar, Pompey and Crassus; Caesar's consulship of 59 BC and its legislation; the sidelining of Bibulus and the Senate; the marriage alliance and the conference of Luca (56 BC); and the significance of the pact for the constitution of the Republic”

13 min readUpdated 1 Jul 2026

Quick answer

In 60 BC Caesar brokered a private, informal, extra-legal compact with Pompey and Crassus, each blocked by the Senate on a separate demand, and sealed it with Julia's marriage to Pompey. As consul in 59 BC he forced through an agrarian law against Bibulus's obstruction and Cato's filibuster (hence "the consulship of Julius and Caesar"), ratified Pompey's eastern settlement, won tax relief for Crassus's publicani, and secured his own five-year Gallic command through the lex Vatinia - every measure driven past the Senate to the People. The pact was renewed at Luca in 56 BC and held until the deaths of Julia (54 BC) and Crassus (53 BC). Its significance is constitutional: three private men decided the state's policy, provinces and armies while the Senate and assemblies kept meeting, reducing the Republic's constitution to a functioning facade.

Jump to a section

What this dot point is asking
The answer
How to read a source on this topic
Historians
Practice questions

What this dot point is asking

This is a Section IV (Historical Periods) dot point, so it is asking you to treat the First Triumvirate as a development in the constitutional history of the late Republic, not as a chapter of Caesar's biography. NESA expects you to explain how a private, informal compact between Caesar, Pompey and Crassus in 60 BC, and Caesar's consulship of 59 BC that delivered on it, weakened the ordinary machinery of Republican government - the Senate's control of policy and provinces, the collegial check of two equal consuls, and the deliberative process itself. You should be able to trace the pact from its formation, through the strong-arm legislation of 59 BC and the sidelining of Bibulus, to its renewal at Luca in 56 BC, and to assess its significance: three men privately deciding the state's business while its institutions kept meeting.

In plain English

Imagine a school where every real decision is supposed to be made by a large staff meeting. Three of the most powerful teachers each have a proposal the meeting keeps voting down. Instead of arguing it out again, they quietly agree over coffee to back one another's proposals and to line up who will chair the meeting next term. Once their ally is chairing, the staff meeting still happens every week, people still raise their hands, minutes are still taken - but the outcome is decided in advance by the three of them. Nothing on paper has changed; in reality the meeting no longer decides anything. That is what 60-59 BC did to the Roman constitution: the Senate and assemblies kept meeting, but three men outside any special office had already settled the important questions between themselves.

The answer

The pact of 60 BC: a private compact, not an office

By 60 BC three of Rome's most powerful men were each blocked by the same optimate bloc in the Senate.

Pompey, back from the East since 62 BC after defeating Mithridates VI and reorganising the eastern provinces and client kingdoms, had disbanded his army in good faith. The Senate, led by his rival Lucullus and by Cato, refused for about three years to ratify his settlement (the Acta of Pompey) as a single package and refused land for his veterans.

Crassus was patron of the publicani (tax-farmers) who held the contract for the province of Asia. Having overbid at auction, they wanted a rebate; Cato led the Senate in refusing it as a bailout of greedy contractors.

Caesar returned from his propraetorship in Further Spain in 60 BC wanting both a triumph and the consulship for 59 BC. Because a candidate had to register in person inside the city (which forfeited the right to a triumph, held only outside the pomerium) and Cato blocked an exemption, Caesar chose the consulship.

Caesar saw that all three were being defeated by the same faction and brokered a reconciliation between Pompey and Crassus, personal rivals since their stormy joint consulship of 70 BC. The three struck a private, informal three-way agreement: Caesar's magistracy and political muscle in exchange for Pompey's veteran support and Crassus's money. Crucially, this was not a magistracy or a legal institution. It created no office, no imperium, no title.

A private deal, not a constitutional office

The "First Triumvirate" is a modern label. Unlike the Second Triumvirate of 43 BC (Antony, Octavian, Lepidus), which was a formal magistracy with statutory powers under the lex Titia, the 60 BC pact had no legal standing whatever - it was a private compact between three citizens. Yet ancient writers recognised it as a single dominant power: Varro's satirical pamphlet Tricaranus ("The Three-Headed Monster") mocked it as one beast ruling through three mouths, and Cicero (ad Atticum, 59 BC) called the emerging domination a "regnum" (kingship).

The pact was sealed as a family alliance: during 59 BC Caesar broke his daughter Julia's existing betrothal and married her to Pompey. By Plutarch's account the arranged match became a genuine and affectionate one, adding a personal bond to the political and financial ones.

The consulship of 59 BC: strong-arm legislation

Caesar and Bibulus, an optimate opposed to the pact, were elected consuls for 59 BC. Caesar dominated from the outset and used a single method - taking bills directly to the People rather than working through the Senate - to deliver every element of the compact.

His lex Julia agraria distributed public land to Pompey's veterans and to poorer citizens; a second, harsher measure divided the ager Campanus near Capua, a rich tract earlier laws had left alone because its rents funded the treasury. A commission of twenty administered it, and Caesar pointedly declined a place to appear less self-interested. When Cato filibustered by speaking through a whole day, Caesar had him arrested; when the Senate rose and followed Cato out in protest, the backlash forced a quiet release.

For Pompey, the Senate's three-year refusal was overridden and his eastern settlement was ratified as a single package. For Crassus, the publicani received a one-third reduction on the Asian tax contract. For Caesar himself, the tribune Publius Vatinius carried the lex Vatinia straight to the tribal assembly, granting Caesar Cisalpine Gaul and Illyricum for an unprecedented five years with three legions; the Senate, fearing the People would grant it anyway, added Transalpine Gaul and a fourth legion. The lex Sempronia of 123 BC had required the Senate to fix consular provinces before elections precisely to stop this; the lex Vatinia sidestepped it entirely.

Sidelining Bibulus and the Senate

The constitutional heart of the year was what happened to the checks meant to restrain a consul.

Bibulus first tried to block the agrarian bill in person and was driven from the Forum, with the fasces of his lictors broken. He then withdrew to his house for the rest of the year and announced he was "watching the skies" (obnuntiatio) for unfavourable omens - a technicality that, if respected, would have voided any business on the remaining assembly days. Caesar and his allies simply ignored it and kept legislating. The result was open mockery: as Suetonius records (Divus Julius 20), contemporaries dated the year's business not to "Bibulus and Caesar" but to "the consulship of Julius and Caesar," naming the same man twice.

Two constitutional principles were gutted in a single year. Collegiality - the check of two equal consuls able to veto each other - was made meaningless when Bibulus's opposition was ignored. And the Senate's control of policy and provinces was bypassed by legislating through the People and by allocating Caesar's command through a tribune. The forms survived; the substance did not.

Renewal at Luca, 56 BC

The pact was not a single event but a renewable arrangement. By 56 BC it was fraying - Cicero, recalled from exile, was attacking the land settlement, and Pompey and Crassus were drifting apart. The three met at Luca (in Caesar's province of Cisalpine Gaul) in 56 BC and renewed the compact: Pompey and Crassus would be consuls together in 55 BC, Caesar's Gallic command would be extended for a further five years, and Pompey and Crassus would then take major provincial commands (Spain and Syria). Luca shows that three private men could set the cycle of magistracies and provincial commands for years in advance. The arrangement held until the deaths of Julia in childbirth (54 BC) and Crassus at Carrhae (53 BC) removed both its personal bond and its three-way balance, after which Caesar and Pompey drifted toward the civil war of 49 BC.

The pact and the constitution at a glance

How to read a source on this topic

Section IV sources on the First Triumvirate typically include contemporary letters, later narrative histories, biographies, and reconstructed inscriptions, edicts or satirical pamphlets referring to the pact, the legislation of 59 BC, Bibulus's obstruction or the conference of Luca. Three reading habits.

First, separate ancient WRITTEN evidence by date and genre. Cicero's letters to Atticus (59 BC) are contemporary and give elite reaction as it happened; Suetonius (Divus Julius) and Plutarch (Lives of Caesar, Pompey, Crassus, Cato) wrote more than a century and a half later as biographers drawing on earlier accounts now lost; Appian (Civil Wars) and Cassius Dio (Roman History) are later narrative historians, useful for the sweep of events but further from the sources.

Second, watch for perspective. Cicero disliked the pact and used the loaded word "regnum"; a later biographer such as Suetonius selects colourful, moralising detail (the "Julius and Caesar" joke) that serves a character portrait. Caesar's own Bellum Gallicum, begun after 58 BC, says almost nothing about 59 BC, because the year did not suit the image he wanted to project - an argument from silence worth noting.

Third, treat satirical or informal material (Varro's Tricaranus, graffiti, recorded jokes) as evidence of PERCEPTION, not neutral record. They show how contemporaries understood the pact as a hidden concentration of power; use them alongside more securely dated evidence rather than instead of it.

Historians

Adrian Goldsworthy (Caesar: The Life of a Colossus, 2006) treats the pact as pragmatic self-interest rather than the opening move of a plan for one-man rule: each man solved an immediate, unrelated problem, and the arrangement was informal and unstable from the start.

Erich Gruen (The Last Generation of the Roman Republic, 1974) cautions against reading the pact as a coherent "conspiracy" against the constitution; he argues that traditional Republican institutions and factional politics continued to operate around and after it, and resists the idea that 60-59 BC made the Republic's fall inevitable.

Ronald Syme (The Roman Revolution, 1939) and Christian Meier (Caesar, 1982) place 60-56 BC within a longer-run crisis in which personal alliances backed by armies and money had already become more decisive than the Senate's authority, whatever any individual's immediate intentions - the frame that reads the pact as a symptom of a constitution no longer able to restrain personal power.

Model responses

1. Source-analysis response (using the Suetonius joke about "Julius and Caesar"). "Suetonius's report that contemporaries dated the year's business to 'Julius and Caesar' rather than 'Bibulus and Caesar' is valuable evidence for how completely one consul had eclipsed his colleague, and so for the collapse of collegiality in 59 BC. Its usefulness lies in showing that this was public mockery, not merely a later historian's verdict; its reliability is limited because Suetonius wrote under Hadrian, more than a century and a half later, and a biographer's anecdote can be sharpened for effect. Corroborated against Cicero's contemporary letters, which describe the same year with alarm, the substance - Bibulus's marginalisation - is well supported even if the exact wording of the joke cannot be verified."

Marker's note: markers reward a response that ties the source to a constitutional point (collegiality), separates content from reliability, and corroborates against an independent contemporary source.

2. Extended-response paragraph (the pact as a hollowing-out of the constitution). "The clearest measure of how far the constitution had become a facade is that its checks were not abolished but rendered inert. Bibulus retained the consulship and its veto, yet was reduced to issuing edicts from his house that everyone ignored; the Senate still met, yet its control of policy and provinces was routed around by legislating through the People and by the lex Vatinia; and at Luca three private men, holding no special office, set the consulships and commands of the following years. Nothing was formally repealed, which is precisely the point: a government whose institutions still function but no longer decide has been hollowed from within, and that is what 60-56 BC achieved."

Marker's note: this paragraph scores because it argues the historical-period thesis - forms preserved, substance drained - from a pattern across several institutions, rather than narrating the events of 59 BC in order.

Command words and how to use a source

Outline/describe wants a small number of clearly separated points; explain wants a point, evidence and why it matters; assess/evaluate/to what extent wants a sustained argument reaching a supported judgement. For a Section IV period question, always pull your answer up to the level of the constitution and the nature of power, not just the personalities.

Using a source properly means four moves every time: (1) content - what it actually shows; (2) reliability - who produced it, when, and why; (3) usefulness - what specific question it helps answer, and how far; (4) perspective - whose viewpoint it represents and what it omits. A response that only describes Source A or B earns little; one that moves content, reliability, usefulness, perspective, then judgement earns full marks.

Weaving in historiography means using a named position as part of the argument, e.g. "as Gruen (1974) argues, the institutions kept functioning, which complicates any claim that the Republic had already fallen" - deployed to test a claim, not dropped in as an unconnected quotation.

Common exam traps

Treating it as a Caesar biography: In Section IV the pact is a constitutional development: focus on what it did to the Senate, collegiality and the provincial system, not on Caesar's career for its own sake.
Calling the Triumvirate an office: It had no legal basis in 60 BC; only the Second Triumvirate of 43 BC was statutory, under the lex Titia. Losing this contrast loses marks.
Narrating 59 BC in order instead of arguing: Listing "agrarian law, then ratification, then lex Vatinia" scores poorly; explain how each bypassed a specific constitutional check.
Stopping in 59 BC: The renewal at Luca (56 BC) is essential evidence that the arrangement was systemic and renewable, not a single crisis - and the deaths of Julia (54 BC) and Crassus (53 BC) explain why it eventually broke.
Forgetting Crassus: Many answers cover Caesar and Pompey and mention Crassus only in passing; the tax relief for the publicani is a distinct, examinable outcome.

Practice questions

Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.

foundation3 marks

Outline what the phrase 'First Triumvirate' means and why it is misleading as a description of the arrangement of 60 BC.

Show worked solution →

A 3-mark "outline" needs a definition, the modern origin of the label, and the key contrast that makes it misleading.

Definition: The "First Triumvirate" is the modern name for the informal political alliance formed in 60 BC between Julius Caesar, Pompey and Crassus to pool their votes, money and influence (1 mark).
Modern label: The term is applied by later historians; contemporaries did not use it as an official title, and the pact was kept private at first (1 mark).
Why misleading: Unlike the Second Triumvirate of 43 BC, which was a formal magistracy created by the lex Titia with statutory powers, the 60 BC compact had no legal standing at all - it was a private agreement between three citizens (1 mark).

Marker's note: markers reward the explicit contrast with the statutory Second Triumvirate, not just a definition of the word "triumvirate."

foundation4 marks

Outline the separate grievances that led Caesar, Pompey and Crassus to combine in 60 BC.

Show worked solution →

A 4-mark "outline" needs each man's grievance named plus the common obstacle.

Pompey: The Senate, led by Lucullus and Cato, had for about three years refused to ratify his eastern settlement as a package and refused land for his veterans (1 mark).
Crassus: He wanted relief for the publicani (tax-farmers) who had overbid on the Asian tax contract and could not pay; Cato blocked the rebate (1 mark).
Caesar: Returning from Spain in 60 BC, he was forced by Cato to choose between a triumph and standing for the consulship, and needed backing to win and use a dominant consulship (1 mark).
Common obstacle: All three were blocked by the same optimate bloc in the Senate, above all Cato, which made a combined push attractive (1 mark).

Marker's note: markers reward three separately named grievances plus recognition that a shared enemy (the optimates) made the alliance logical.

foundation4 marks

Outline the terms of the lex Vatinia of 59 BC and why it mattered constitutionally.

Show worked solution →

A 4-mark "outline" needs the proposer, the province and term, the force, and the constitutional point.

Proposer and method: The tribune Publius Vatinius put the law directly to the tribal assembly, bypassing the Senate's normal right to allocate provinces (1 mark).
Province and term: It gave Caesar Cisalpine Gaul and Illyricum for an unprecedented five years, far longer than the usual one-year proconsular term (1 mark).
Force: An initial command of three legions, raised to four when the Senate added Transalpine Gaul (1 mark).
Constitutional point: The lex Sempronia of 123 BC required consular provinces to be fixed by the Senate before the elections precisely to prevent this manipulation; the lex Vatinia sidestepped that safeguard (1 mark).

Marker's note: markers reward all four specific terms plus the constitutional significance, not a vague "big command in Gaul."

core6 marks

Source A: a reconstructed political pamphlet fragment of this type, in the manner of Varro's lost satire Tricaranus ('The Three-Headed Monster'), depicts the government of Rome as a single beast that rules through three mouths while the magistrates look on. Using Source A and your own knowledge, explain what the pact of 60 BC reveals about the health of the Republican constitution.

Show worked solution →

A 6-mark "explain" needs the source read for its viewpoint, the constitutional problem it points to, and supporting knowledge.

Use of the source: Source A represents a hostile, senatorial-aligned perspective: the "three-headed monster" image shows that contemporaries saw the real power of the state as concentrated in three private men, not in the magistracies (1-2 marks).
The constitutional problem: The pamphlet's force depends on a gap between appearance and reality - the consuls, Senate and assemblies still met, but decisions were pre-arranged by three individuals outside any office. This is the essence of the crisis: the forms of the constitution survived while its substance drained away (1-2 marks).
Supporting knowledge: The pact had no legal basis, unlike the later statutory Second Triumvirate; it rested on Pompey's veterans, Crassus's wealth and Caesar's magistracy. Cicero, writing to Atticus in 59 BC, reacted to the same reality with the loaded word "regnum" (kingship), independently confirming that the informality alarmed contemporaries (2 marks).

Marker's note: markers reward candidates who use the source as evidence of PERCEPTION and then connect it to the substantive point that the constitution had become a facade, corroborated by Cicero.

core5 marks

Explain the significance of the conference of Luca in 56 BC for the survival of the pact.

Show worked solution →

A 5-mark "explain" needs the context, what was agreed, and why it mattered.

Context: By 56 BC the pact was fraying: Cicero had been recalled from exile and was attacking the agrarian settlement, Pompey and Crassus were increasingly at odds, and Caesar was absent in Gaul (1-2 marks).
What was agreed: At Luca, in Caesar's province of Cisalpine Gaul, the three men renewed their compact: Pompey and Crassus would hold the consulship of 55 BC together, Caesar's Gallic command would be extended for a further five years, and Pompey and Crassus would afterwards receive major provincial commands of their own (Spain and Syria) (1-2 marks).
Significance: Luca shows the pact was not a one-off deal of 60 BC but a renewable private arrangement that could override the normal cycle of magistracies for years; it kept three men in control of the Republic's armies and provinces and postponed the breakdown until the deaths of Julia (54 BC) and Crassus (53 BC) removed its personal and three-way balance (1 mark).

Marker's note: markers reward candidates who explain Luca as a RENEWAL that prolonged extra-constitutional control, not merely a meeting that happened.

exam8 marks

Source B: a reconstructed edict of this type, issued by the consul Bibulus from his house in the second half of 59 BC, declares that he is 'watching the skies' for omens and that all public business transacted on those days is void. Using Source B and your own knowledge, assess the usefulness and reliability of edicts of this kind as evidence for the conduct of Caesar's consulship.

Show worked solution →

An 8-mark "assess usefulness and reliability" answer needs content, usefulness, reliability, and a supported judgement.

Content: Source B shows Bibulus, Caesar's consular colleague, attempting to invalidate Caesar's legislation by religious obstruction (obnuntiatio) - announcing unfavourable omens rather than opposing the bills in open debate (2 marks).
Usefulness: Such an edict is highly useful as evidence that ordinary opposition had already failed: Bibulus had been driven from the Forum and his fasces broken, so he retreated to a technicality. It shows the collegial veto, a core check on a consul, being reduced to a paper protest (2 marks).
Reliability and limitation: As an official act it is reliably dated to Bibulus's consulship, but it is one-sided: it records his claim, not its effect. On its own it could mislead a reader into thinking the business really was voided, when in fact Caesar simply ignored it and kept legislating (2 marks).
Judgement: The edict is most reliable as evidence of the tactic and of the breakdown of collegiality, and least reliable as a guide to outcomes; it must be read alongside Suetonius (Divus Julius 20), who records that the year was mockingly dated to "the consulship of Julius and Caesar," and Cicero's contemporary letters, which confirm Bibulus's near-total withdrawal (2 marks).

Marker's note: markers reward candidates who separate the tactic (well evidenced) from its outcome (not shown by the edict) and corroborate against named ancient authors.

exam25 marks

To what extent did the First Triumvirate and Caesar's consulship of 59 BC reduce the constitution of the Roman Republic to a facade? In your response, refer to relevant sources and the interpretations of historians.

Show worked solution →

A Band-6 response needs a thesis, four argument lines tied to dated evidence, historiography and a counter-view, a model paragraph, and a judgement.

Thesis: To a very large extent: across 60-56 BC the outward forms of the constitution continued to function while their substance was hollowed out, because three private men could pre-decide the state's major business and neutralise every check designed to prevent exactly that.
Argument 1 - the pact itself was extra-constitutional: The 60 BC compact had no statutory basis, unlike the Second Triumvirate created by the lex Titia in 43 BC. It was a private agreement among three citizens, satirised in Varro's Tricaranus and alarming Cicero enough to write of a forming "regnum" (ad Atticum, 59 BC).
Argument 2 - the legislation of 59 BC bypassed the Senate: Caesar took his agrarian bill straight to the People, had Cato arrested mid-filibuster, and delivered Pompey's ratified eastern settlement and Crassus's tax rebate in a single year - all matters the Senate had blocked. The proper deliberative body was simply routed around.
Argument 3 - collegiality was made meaningless: Bibulus, the other consul, was driven from the Forum and reduced to "watching the skies"; his obnuntiatio was ignored, producing the taunt "the consulship of Julius and Caesar." The constitution's central check on a consul, an equal colleague, ceased to operate.
Argument 4 - the pact was renewable, not a single crisis: At Luca in 56 BC the three renewed the deal: consulships for Pompey and Crassus in 55 BC, an extended Gallic command for Caesar, and provinces to follow. Extra-constitutional control was not an accident of one year but a system sustained across half a decade.
Counter-view: Ratifying Pompey's settlement and easing the publicani's burden were arguably overdue; direct popular legislation was itself a legitimate, if aggressive, exercise of Republican sovereignty. Gruen argues the institutions kept functioning and warns against reading a settled "conspiracy" into events that were often improvised.
Historiography: Goldsworthy (2006) sees pragmatic self-interest rather than a plan for monarchy. Gruen (1974) resists the facade reading, stressing that traditional politics continued. Syme (1939) and Meier (1982) place 60-59 BC within a longer crisis in which armies and money had already outweighed the Senate's authority.
Model paragraph: "The decisive evidence is not any single law but the pattern: the Senate bypassed, the colleague neutralised, the tribunate and the provincial system turned into instruments of a private deal, and the whole arrangement renewed at Luca. Each institution still met and still voted; none any longer decided. A constitution whose forms survive while three men outside them settle every important question is, in substance, a facade."
Judgement: To a very large extent the constitution became a facade, though a functioning one - the forms were preserved and even used, which is precisely why the hollowing-out was so effective and so hard to resist.

Marker's note: markers reward a sustained answer to "to what extent," at least four dated pieces of evidence, engagement with historiography AND a counter-view, and a paragraph that argues from a pattern rather than narrating the year in order.

Practise this

Sources & how we know this

Ancient History Stage 6 Syllabus (2017) — NESA
Ancient History HSC exam papers — NESA