The Roman expeditionary force set sail from Constantinople in late June 533, and after a sea voyage along the coasts of Greece and southern Italy, landed on the African coast at Caputvada in early September, to Gelimer's complete surprise. The Vandal king gathered his forces and met the Roman army at the Battle of Ad Decimum, near Carthage, on 13 September. Gelimer's elaborate plan to encircle and destroy the Roman army came close to success, but Belisarius was able to drive the Vandal army to flight and occupy Carthage. Gelimer withdrew to Bulla Regia, where he gathered his remaining strength, including the army of Tzazon, which returned from Sardinia. In December, Gelimer advanced towards Carthage and met the Romans at the Battle of Tricamarum. The battle resulted in a Roman victory and the death of Tzazon. Gelimer fled to a remote mountain fortress, where he was blockaded until he surrendered in the spring.