The city was sacked by a Berber revolt in 371 and 372. It largely recovered, but was ravaged again by the Vandals after they were invited into Roman North Africa by Count Boniface in 429. Parts of the town received new fortifications. After the Vandal Kingdom conquered Carthage in 439, they also acquired a large part of Rome's Mediterranean fleet which they used to carry out raids all over the sea. Caesarea's port was sometimes used as a base for these raiders, and the city prospered from their plunder. Its schools produced the famous grammarian Priscian, who emigrated to the Byzantine east.