Hasdingi Vandals were defeated by a joint Roman-Suebi coalition. Gunderic fled to Baetica, where he was also proclaimed king of the Silingi Vandals. In 422 Gunderic decisively defeated a Roman-Suebi-Gothic coalition led by the Roman patrician Castinus at the Battle of Tarraco. It is likely that many Roman and Gothic troops deserted to Gunderic following the battle. For the next five years, according to Hydatius, Gunderic created widespread havoc in the western Mediterranean. In 425, the Vandals pillaged the Balearic Islands, Hispania and Mauritania, sacking Cartagena and Seville in 425. The capture of the maritime city of Cartagena enabled the Vandals to engage in widespread naval activities. In 428 Gunderic captured Seville for a second time but died while laying siege to the city's church. He was succeeded by his half-brother Genseric, who although he was illegitimate (his mother was a slave) had held a prominent position at the Vandal court, rising to the throne unchallenged. In 429 The Vandals departed Spain which remained almost totally in Roman hands until 439, when the Sueves, confined to Gallaecia moved south and captured Emerita Augusta (Mérida), the see city of Roman administration for the whole peninsula. Genseric is often regarded by historians as the most able barbarian leader of the Migration Period. Michael Frassetto writes that he probably contributed more to the destruction of Rome than any of his contemporaries. Although the barbarians controlled Hispania, they still comprised a tiny minority among a much larger Hispano-Roman population, approximately 200,000 out of 6,000,000. Shortly after seizing the throne, Genseric was attacked from the rear by a large force of Suebi under the command of Heremigarius who had managed to take Lusitania. This Suebi army was defeated near Mérida and its leader Hermigarius drowned in the Guadiana River while trying to flee. It is possible that the name Al-Andalus (and its derivative Andalusia) is derived from the Arabic adoption of the name of the Vandals. Kingdom in North Africa Establishment The Vandals under Genseric (also known as Geiseric) crossed to Africa in 429. Although numbers are unknown and some historians debate the validity of estimates, based on Procopius' assertion that the Vandals and Alans numbered 80,000 when they moved to North Africa, Peter Heather estimates that they could have fielded an army of around 15,000–20,000. According to Procopius, the Vandals came to Africa at the request of Bonifacius, the military ruler of the region.