During the later stages of the Gallic War he commanded two legions on the southern slope of the heights during the siege of Alesia, where Caesar's defences were weakest. With great difficulty, and the timely support of Titus Labienus, he withstood the last major attack on the Roman position there on October 2, 52 BC. The following year he was sent to pursue Cadurci leader Lucterius, who fled to the stronghold of Uxellodunum which Rebilus proceeded to besiege. Attempting to emulate the tactics at Alesia, he was forced to deal with repeated sorties which disrupted his attempts to complete his lines. Eventually Caesar made his way there to take overall command of the siege.