Following the Norman conquest of the 1120s, Malta was integrated with the County, then the Kingdom of Sicily, and as such included within the Norman–Byzantine cultural sphere. The new rulers released and sent back to their homes those Christian slaves still present on the islands, but also brought with them a number of Greeks, who were disproportionately represented in the Norman–Sicilian navy. During the brief existence of a Norman kingdom in Africa, Greek administrators participated in repressing Arab piracy. A poem by a Greek exile to Malta, probably authored ca. 1150, laments that the population was still mostly Muslim, and commends the Normans for their efforts to convert them.