Thirty-nine days after the disastrous Nika Riots ended with the slaughter of 30,000 civilians, Justinian directed the city to rebuild the Hagia Sophia. Together, they built an even greater cathedral - but Justinian was not satisfied. He was called a Roman emperor, but he did not rule Rome itself. He resolved to reconquer the west, starting with Carthage in Africa, which had been conquered by Vandal tribes and turned into the seat of their budding empire. When the cousin of the Vandal king overthrew him for being pro-Roman and a follower of Rome's orthodox Christianity, Justinian had his excuse for war. He stirred up rebellion in the Vandal colonies, creating a distraction while he sent his general Belisarius to Carthage with a small army of men. Belisarius landed successfully and moved on Carthage, winning the support of the local people on his way. Gelimer teamed up with his brothers in two separate attempts to crush Belisarius and drive him out of Carthage, but after both of his brothers died, Gelimer lost his will to fight. He broke, and the Vandal resistance broke with him. Justinian awarded Belisarius a triumph, the greatest honor a Roman general could receive, but it would turn out to be the last formal triumph Rome would ever see.