The siege of Gomphi (48 BC) was a minor victory won by Caesar in the period between his defeat at Dyrrhachium in May and his victory at Pharsalus in August (Great Roman Civil War). Caesar had attempted to besiege Pompey in his camp at Dyrrhachium, but on 20 May Pompey had broken through Caesar's lines. In the aftermath of this defeat Caesar had decided to retreat east into Thessaly, with Pompey following cautiously behind.
At Aeginium Caesar joined up with another of his armies, under Gnaeus Domitius Calvinus. The combined army then advanced along the road from Epirus to Thessaly, an area that had originally promised to support Caesar. News of Pompey's victory at Dyrrhachium arrived before Caesar, and helped convince Androsthenes, praetor of Thessaly, to side with Pompey instead. As Caesar approached Gomphi, which he described as the first town in Thessaly on the road from Epirus, Androsthenes sent messengers to Pompey and Scipio asking for help, and prepared to defend the town.
Caesar didn’t give Pompey time to send help. On the day he arrived outside Gomphi his men built their camp and were then ordered to build siege equipment. The assault began just after 3 in the afternoon, and the city fell before sunset. Caesar's men, who had been short of supplies, were allowed to plunder the town. According to Appian Caesar's men got so drunk that Pompey could have won an easy victory if he hadn't been following so far behind. Appian also reports that twenty of the leading citizens of the city were found dead in an apothecary's shop having committed suicide, the price for choosing the wrong side in the Roman civil war.
After taking Gomphi Caesar advanced to Metropolis. News of the fate of Gomphi arrived before him, and the citizens of Metropolis promptly welcomed him into their town. Much of Thessaly did the same. Caesar moved on to Pharsalus, where the decisive battle of the campaign would be fought.