In 54 BC Pompey's young wife had died and with her death had disappeared the personal link between him and his father-in-law Caesar.
Crassus had started for the east to take up governorship of Syria. Meanwhile Pompey did little. He simply watched with growing jealousy the successive triumphs of Caesar in Gaul.
In 52 BC things in Rome reached another point of crisis. During the previous two years the city had remained in a state of near anarchy.
Clodius, still the leader of the popular extremists, was killed in an violent brawl with the followers of Milo, the leader of the senatorial extremists. Pompey, was elected sole consul and was commissioned to restore order in the ever more riotous city of Rome.
In effect Pompey was left virtual dictator of Rome. A dangerous situation, considering Caesar's presence in Gaul with several battle-hardened legions.
Pompey himself achieved a five year extension for his own position of proconsul of Spain, but - very controversially - he had a law passed by which Caesar's term in Gaul would be cut short by almost a year (ending in March 49 instead of January 48 BC).
A reaction of Caesar's was inevitable to such provocation, but he could not respond immediately, as a large scale revolt in Gaul demanded his full attention.