Castinus

In 422 he fought an unsuccessful campaign in Hispania to subdue the Vandals. He was sent to support the Suevi or Swabians, enemies of the Vandals, and came with a force of Gothic foederati. However, the campaign was compromised from the very beginning as he was accompanied by the military tribune Bonifacius, a very experience court official and a protege of Galla Placidia, the wife of Constantius III and the mother of Valentinian III, the emperor Joannes would try to usurp. Unsurprisingly there was rivalry between Castinus and Bonifacius, and the latter returned to Italy with his troops, while Castinus, who remained, was defeated by the Vandals and had to withdraw to Tarragona.

When the Eastern Emperor Theodosius II hesitated to nominate a new emperor of the West, Castinus took it upon himself to declare Joannes, the senior civil servant, as the new Western Emperor.

Castinus himself was consul the next year (424). However, Joannes was an insecure emperor, the majority of the empire was still loyal to the House of Theodosius. Joannes was captured and executed in June/July 425, and it is likely that Castinus shared the same fate.