The Sequani reward Ariovistus with land in 61 BCE following his victory in the Battle of Magetobriga.

Ariovistus settles the land with one hundred and twenty thousand of his people.

When twenty-four thousand Harudes join his cause, Ariovistus demand that the Sequani give him more land to accommodate the Harudes people.

This demand 'concerns' Rome because if the Sequani concede, Ariovistus will be in a position to take all of the Sequani land and attack the rest of Gaul.

By this time, the Helvetii are well on their way in the planning and provisioning for a mass migration under the leadership of the wealthy aristocrat Orgetorix, who has persuaded the Helvetians to attempt to migrate from Helvetian territory to southwestern Gaul (modern-day France).

The reasons for their migration are mentioned by Caesar in separate passages as either harassment by the Germanic tribes, or not being able to in turn raid for plunder themselves due to their situation in hilly and mountainous territory.

Via council and parley, Orgetorix makes clandestine negotiations with the ambitious Sequani and the Roman-dominated Aedui.

The Sequani are beginning to resent and regret the abundance of unruly Germanic war bands and their huge encampments of dependents.

The Aedui are loath to obey the Roman spur any longer than they must and are keen to revisit their former days at council.

The parley for the trek is successful and Orgetorix is granted passage, and with the trek ratified by council, an army is called up and provisioned.

During this process, Orgetorix had also succeeded in making a personal alliance with the Sequanii chieftain Casticus and the Aedui chieftain Dumnorix through marital arrangements and host exchange of family members.

Orgetorix's Gallic rivals allege that these political successes and displays of diplomacy are intended to benefit Orgetorix alone and their claims are made more convincing by Roman intrigues and impositions.

Caesar, in Spain, has conquered two local tribes and is hailed as imperator by his troops, reforms the law regarding debts, and completes his governorship in high esteem.

Caesar’s military expedition beyond the northwest frontier of his province has enabled him to win loot for himself as well as for his soldiers, with a balance left over for the treasury.

As imperator, Caesar is entitled to a triumph.

However, he also wants to stand for consul, the most senior magistracy in the republic.

If he were to celebrate a triumph, he would have to remain a soldier and stay outside the city until the ceremony, but to stand for election he would need to lay down his command and enter Rome as a private citizen.

He cannot do both in the time available.

He asks the senate for permission to stand in absentia, but Cato blocks the proposal.

Faced with the choice between a triumph and the consulship, Caesar chooses the consulship.

The value of the consulship lies in the lucrative provincial governorship to which it would normally lead.

On the eve of the consular elections for 59, the Senate seeks to allot to the two future consuls for 59, as their proconsular provinces, the unprofitable supervision of forests and cattle trails in Italy.

The Senate also secures by massive bribery the election of an anti-Caesarean, the conservative Marcus Calpurnius Bibulus, but they fail to prevent Caesar's election as the other consul.

The election is sordid—even Cato, with his reputation for incorruptibility, is said to have resorted to bribery in favor of one of Caesar's opponents.

Caesar invites Cicero to be the fourth member of his existing secret partnership with Pompey and Crassus, an assembly that will eventually be called the First Triumvirate.

Cicero refuses the invitation because he suspects it will undermine the Republic.

The lands that had been originally assigned to the Roman people by Publius Cornelius Scipio Africanus, but were subsequently acquired by Numidia as part of the treaty with Rome, are expressly exempted from sale when the tribune Publius Servilius Rullus introduced his agrarian law in 63 BCE.

This had roused the indignation of Cicero (De lege agraria, i.4, ii.22).

From Suetonius (Caesar, 71) it is evident that Hiempsal II, king of Numidia, was alive in 62 BCE.

Hiempsal had in 81 BCE been driven from his throne; Pompey had been sent to Africa by Sulla soon afterwards to reinstate Hiempsal as king in Numidia.

Because of this, Hiempsal and later his son Juba, who succeeds Hiempsal in 60 BCE, had become Pompey’s allies.

According to Sallust (Jugurtha, 17), Hiempsal was the author of an historical work in the Punic language.

Rome has begun in recent decade to exercise stronger influence on the Getae.

Roman merchants have arrived to exchange goods, and the Getae have begun counterfeiting Roman coins.

The Getae, or Geto-Dacians, have revived their old tribal union under the leadership of Burebista (reigned 82-44 BCE), who has amassed formidable military power with the help of the high priest Deceneu.

Cogaionon, the sacred mountain of the Dacians, is at the center of the kingdom's nucleus in the area of the iron-rich Orastie mountains in the southern Carpathians.

In 60-59, Burebista campaigns successfully against the Celts who threaten his kingdom from the northeast.

Ptolemy XII Auletes, facing serious opposition from the people of Alexandria and still unsure of his status at Rome, bribes Caesar with six thousand talents, in return for which Caesar passes a law acknowledging his kingship over Egypt.

Caesar, faced with inflexible opposition from such conservative Senators as Lucullus and Cato the Younger, now succeeds in organizing an irresistible coalition of political bosses.

He is already in Crassus' political debt, but he has also made overtures to Pompey, assiduously cultivating his friendship.

Pompey and Crassus have been at odds for a decade, so Caesar tries to reconcile them.

The three of them have enough money and political influence to control public business.

This informal alliance, known as the First Triumvirate ("rule of three men"), is cemented by the marriage of Pompey to Caesar's only child, Julia, in April 59.

This family alliance of its two great chiefs is regarded as the firmest bond between Caesar and Pompey, and is accordingly viewed with much alarm by the optimates (the oligarchal party in Rome), especially by Cicero and Cato the Younger.

Caesar also marries again, this time Calpurnia, As consul, Caesar champions a bill of Publius Servilius Rullus for the redistribution of Roman public lands in Italy to the poor, on which the first charge is to be a provision for Pompey's soldiers.

The proposal is supported by Pompey, by force of arms if need be, and by Crassus, making the triumvirate public.

Three tribunes of the plebs veto the bill, and Caesar's colleague Bibulus announces his intention of preventing the transaction of public business by watching the skies for portents whenever the public assembly is convened.

Pompey fills the city with soldiers, a move which intimidates the triumvirate's opponents.

Bibulus attempts to declare the omens unfavorable and thus void the new law, but is driven from the forum by Caesar's armed supporters.

His bodyguards have their ceremonial axes broken, two high magistrates accompanying him are wounded, and he has a bucket of excrement thrown over him.

In fear of his life, he retires to his house for the rest of the year, issuing occasional proclamations of bad omens.

These attempts to obstruct Caesar's legislation prove ineffective.

Roman satirists ever after referred to the year as "the consulship of Julius and Caesar."

In the same year, Clodius, who had been acquitted of the sacrilege charge in 61 by a jury probably bribed by Crassus, renounces his patrician status, is adopted into a plebian gens, and is elected a Tribune of the plebs.

Pompey's settlement of the East is ratified en bloc by an act negotiated by an agent of Caesar, the tribune of the plebs Publius Vatinius.

Caesar himself initiates a noncontroversial and much-needed act for punishing misconduct by governors of provinces.

Another act negotiated by Vatinius gives Caesar Cisalpine Gaul (between the Alps, the Apennines, and the Adriatic) and Illyricum.

When Metelus Celer, the governor-designate of Transalpine Gaul (southern France) suddenly dies, this province, also, is assigned to Caesar at Pompey's instance, giving him four legions.

Cisalpine Gaul gives Caesar a military recruiting ground; Transalpine Gaul gives him a springboard for conquests beyond Rome's northwest frontier.

The term of his governorship, and thus his immunity from prosecution, is set at five years, rather than the usual one; his tenure is to last until February 28, 54.

When his consulship ends, Caesar narrowly avoids prosecution for the irregularities of his year in office, and quickly leaves for his province.

Rome nevertheless divests Egypt of Cyprus the next year, when the Roman demagogue Clodius Pulcher annexes the island—driving its king to suicide when his brother in Egypt fails to support him—to pay for his massive grain distributions in Rome.

Cato the Younger is sent by a law of Clodius to oversee the annexation of the island.

Marcus Junius Brutus—whose mother, Servilia, is a half-sister of Cato the Younger and reputed mistress of Caesar—is adopted by Quintus Servilius Caepio and takes the name Quintus Caepio Brutus.

Brutus in 58 at the age of about twenty-seven accompanies Cato to Cyprus.

The Helvetii have planned and prepared themselves for three years, and emissaries have been sent out to various Gallic tribes assuring safe passages and alliances.

In 58 BCE, Orgetorix's ambitions are declared a ruse for personal power; this rumor is celebrated among the enemies of the Helvetii, especially those of Roman clientele.

This succeeds in causing confusion and feuds among the tribes, based mainly on the merits of Orgetorix versus his vices.

The conspiracy is denounced; Orgetorix is called to a hearing in chains before the government of the Helvetii.

There is an effort to seize him at council, however he is protected by his retinue and bodyguards.

During the preceding seasons he had called up a sizable force of men-at-arms and vassals said to have numbered ten thousand men, this in addition to his armed entourage.

Orgetorix is able to escape capture by his rivals and the councils labor at length to resolve the confusions and disputes; however, Orgetorix is murdered or slain during a dispute within his own encampment With many conflicts of interest settled, the Helvetii once again return to their long planned migration to safer pastures among the Santones tribe on the Atlantic seaboard.

Caesar dates their departure to the twenty-eighth of March, and mentions that they burned all their towns and their villages so as to discourage thoughts among undecided client tribes or enemies to occupy their vacated realm.

The Helvetii retain and arm their client tribes: the Rauraci, the Tulingi, the Latovici, and the Boii, from whom they have hired a contingent of horsemen.

There are two available routes for them: the first one is the difficult and dangerous Pas de l'Ecluse, located between the Jura mountains and the Rhône River.

The second, easier one will lead them to the town of Geneva, where Lake Geneva flows into the Rhone River and where a bridge allows passage over the river.

These lands belong to the Allobroges, a tribe that had been subdued by Rome, and are under the control of the Roman republic.

Meanwhile, Caesar is in Rome, and only a single legion is in Transalpine Gaul, the endangered province.

As he is informed of these developments, he immediately hurries to Cisalpine Gaul, leaving his single legion under the command of his second-in-command Titus Labienus.

Upon arrival, he takes command of the three legions which were in Aquileia and enrolls two new legions, the Legio XI and the Legio XII.

At the head of these five legions, he travels the quickest way through the Alps, crossing territories of several hostile tribes and fighting several skirmishes en route.

Arriving in Geneva, he orders a levy of several auxiliary units and the destruction of the bridge.

The Helvetii send an embassy under the new leadership of Nammeius and Verucloetius, to negotiate a peaceful passage, promising to do no harm.

Caesar stalls the negotiations while his troops fortify their positions behind the river with a sixteen foot high rampart and a parallel trench lined with ballistas; his legionaries are backed by mercenary archers and slingers and Caesar has also hired and/or conscripted a contingent of Gallic horseman from the Remi.

As the embassy returns, Caesar officially refuses their request and warns them that any forceful attempt to cross the river will be opposed.

Several attempts are quickly beaten off.

The Helvetii turn back and enter negotiations with the Sequani to let them pass in a peaceful manner.

Gaius Julius Caesar ends his consulship in Rome in 58 BCE.

Due to the costs of consulship, Caesar is still deeply in debt, and there is money to be made as a governor, whether by extortion or by military adventurism.

Having secured the governorship of both Cisalpine Gaul and Transalpine Gaul, Caesar initially has four veteran legions under his direct command: Legio VII, Legio VIII, Legio IX Hispana, and Legio X.

As he had been governor of Hispania Ulterior in 61 BCE and had campaigned successfully with them against the Lusitanians, Caesar knows personally most (perhaps even all) of these legions.

Caesar also has the legal authority to levy additional legions and auxiliary units as he sees fit.

His ambition is to conquer and plunder some territories to get himself out of debt, and it is likely Gaul was not his initial target, but that he was instead planning a campaign against the kingdom of Dacia located in the Balkans.

The nations of Gaul are civilized and wealthy.

Most have contact with Roman merchants and some, particularly those that are governed by Republics such as the Aedui and Helvetii, have enjoyed stable political alliances with Rome in the past.

Two of Caesar’s provinces border on unconquered territory, and parts of Gaul are known to be unstable.

Some of Rome's Gallic allies have been defeated by their rivals, with the help of a contingent of Germanic tribes.

The Romans fear these tribes are preparing to migrate south, closer to Italy, and that they have warlike intent.

The threat of invasion by the Helvetii, a German-Celtic tribe from the area that is now Switzerland, gives Caesar a pretext to advance his career through war.

His personal ambitions extending far beyond his proconsulship of Cisalpine and Transalpine Gaul, Caesar goes to war in Gaul, ostensibly to protect the Roman republic's Mediterranean holdings.