Following the Muslim conquest of Sicily, from 902 the theme was limited to Calabria, but retained its original name until the middle of the 10th century.

Ever since its reconquest from the Ostrogoths by Belisarius in 535–536, Sicily had formed a distinct province under a praetor, while the army was placed under a dux.

It comprised not only the island, which was divided into districts called tourmai, but also the mainland duchy of Calabria (Greek: δουκᾶτον Καλαυρίας, doukaton Kalavrias), which extended roughly up to the river Crati.

[4][5][6] The strategos of Sicily exercised some authority—varying according to the prevailing local political faction—over the autonomous duchies of Naples, Gaeta and Amalfi.

Following the fall of Syracuse in 878 and the conquest of Taormina in 902, the strategos moved to Rhegion, the capital of Calabria.