The occasion for the invasion of Sicily was provided by the rebellion of the Euphemius, commander of the island's fleet. Euphemius resolved to seek refuge among the Empire's enemies and with a few supporters sailed to Ifriqiya. There he sent a delegation to the Aghlabid court, which pleaded with the Aghlabid emir Ziyadat Allah for an army to help Euphemius conquer Sicily, after which he would pay the Aghlabids an annual tribute. Asad was placed at the head of the expedition. The Muslim expeditionary forces are said to have consisted of ten thousand foot soldiers and seven hundred cavalry, mostly Ifriqiyan Arabs and Berbers, but possibly also some Khurasanis. The fleet comprised seventy or a hundred ships, to which were added Euphemius' own vessels.

The Muslim conquest of Sicily began in June 827 and lasted until 902, when the last major Byzantine stronghold on the island, Taormina, fell. Isolated fortresses remained in Byzantine hands until 965, but the island was henceforth under Muslim rule until conquered in turn by the Normans in the 11th century.