As Caesar returned from his second expedition to Britain in 54 BC, there was already trouble looming in Gaul and in his personal life. He received word that his daughter Julia, wife of Pompey had died in childbirth. This event was assuredly difficult for Caesar on a personal level, but it carried monumental political ramifications as well. While Julia lived Pompey remained at least partially allied to Caesar, but with her death, he drifted ever closer to Caesar's enemies, the boni. Caesar attempted to confirm the alliance by offering his grandniece Octavia as a new bride to Pompey, while also offering to divorce his own wife and marry Pompey's daughter. Pompey's refusal, though an indication of his own personal grief, was also a clear signal that the triumvirate was slowly breaking apart. With the death of Crassus at Carrhae two years later, the coming civil war seemed inevitable. Shortly after word of Julia's death, Caesar also received the news of the death of his mother Aurelia. With the Gallic revolt on the horizon, and the recent tragic news, 54 BC was shaping into a terrible year for Caesar.
For now though, despite his personal and political losses, Caesar had to deal with revolts in Gaul and renewed trouble with Germanic tribes. Legions were scattered throughout Gaul for the winter camps, to not only quell trouble, but to spread the burden of supply throughout the province. One camp in particular, that of Cotta and Sabinus, was sent to cover the Rhine area in the territory of the Eburones. A surprise ambush dealt Caesar's legions its first major defeat and opened the door for widespread revolution. The battle, conducted by Ambiorix, was a prolonged affair in which the Romans fought valiantly to nearly the last man. 15 cohorts were slaughtered, totaling nearly 7,200 men or just under ¼ of Caesar's total force. Only a few scattered remains of the army were able to escape to the camp of Labienus some distance away, and if not for these men, the story of the lost cohorts may have been a complete mystery.
The Gauls and Ambiorix found it easy to recruit after this victory and their army swelled to as many as 60,000 warriors. They next moved on the camp of Quintus Cicero, brother of the great orator, and laid siege. Caesar, with a much smaller force of some 7,000 men was able to defeat the poorly equipped and trained Gallic mob, but found Cicero and his men near utter disaster. Nine in every ten men under Cicero's command had been reported as wounded, and Caesar procured them with great military honors for their service. Caesar and Cicero moved to Samarobriva in December to finally settle in to winter quarters. At the camp of Labienus, he was under constant pressure from Eburones, Nervii and Treveri cavalry. Word of Caesar's victory, and the killing of the Treveri leader Indutiomarus in a Roman raid led by Labienus relieved the pressure, but the situation remained unclear for the entire winter of 54 to 53 BC.
At the offset of 53 BC, Caesar trained two new legions and borrowed a third from Pompey. Clearly Pompey and Caesar hadn't completely fallen out yet, but this could've been done to force Caesar into Pompey's debt. Regardless, Caesar now had 10 full legions under his command and he would begin to put them to use as early as March. Caesar first punished the Nervii for their involvement in the revolt and identified other opposing tribes as the Senones, Carnutes, Treviri, Eburones and Menapii. He secured a headquarters in central Gaul at Lutetia and marched against the Senones, Carnutes and Menapii. Winning victory easily, Caesar reinforced Labienus in facing the Treviri and their Germanic allies whom had been crossing the Rhine. Labienus soundly defeated this opposition, bringing northeastern Gaul under Roman dominion once again, and Caesar was able to focus his attention on the source of many Gallic disruptions, the Rhine.
In the summer of 53 BC, Caesar once again bridged the Rhine to pursue Ambiorix and the Eburones. In a few short weeks, the land of the Eburones was decimated, though Ambiorix escaped Caesar's grasp. Caesar's Germanic allies the Ubii, punish the Suevi on his behalf for aiding the Treviri against Labienus and for just being a general source of trouble. At the end of this short trip, despite some harrowing moments for Qunitus Cicero who was once again besieged as his small force guarded the Rhine bridge, the expedition resulted in Caesar's favor.
At the end of the campaign year of 53 BC, general peace seemed to have returned to Gaul, and Caesar was able to revisit Cisalpine Gaul to attend to political and administrative matters. By this time however, word had arrived of Crassus' great defeat to the Parthians at Carrhae, and coupled with the death of Julia, it was obvious that the political situation would begin to unravel. Immeasurable bribery was taking place in Rome along with lawsuits and trials of all sorts. The mob violence between Clodius and Milo continued and elections for 53 had been delayed until summer; just about the time that Caesar made his second crossing of the Rhine.
By early 52 BC, the situation in Rome was no better and in fact had grown much worse. Mob violence prevailed and elections were delayed once again. The violence between Clodius and Milo eventually resulted in the murder of Clodius and the trial of Milo, resulting in his exile. In an emergency, Pompey wanted the dictatorship, but the optimates or 'boni', were still concerned over Pompey's motivation. Instead, he was offered effectively the same position without the title. He was made sole Consul for the year, so was able to rule more effectively than with a potential rival, but still wasn't graced with the power of the Tribunes. Pompey then married into the boni clan marrying Claudia, the daughter of Quintus Caecilius Metellus Pius Scipio. Metellus was eventually made join Consul to ease fears over Pompey's power, but by now Pompey was clearly leaning with Caesar's enemies. A law was passed to prevent the great amount of electoral bribery that was running rampant, and in it, magistrates were once again forced to run for office only if they were present in Rome. Pompey had previously told Caesar that an exception would be made for him to protect him from his enemies and allow him to regain imperium through public office at the end of his Gallic term. As the boni were anxiously awaiting his term to run out which would force him to return to Rome without the protection of his legions, this clause was of paramount importance to Caesar. However, the exception was 'accidentally' left out of the final draft and it was becoming painfully clear that the boni intended to cut down Caesar's career at any cost.