sentences:  During this period, the population developed an economy based on self-sufficiency and piracy, and even showed evidence of a relative hierarchy.The dominant groups took advantage of the Byzantine withdrawal due to Islamic expansion across the Mediterranean, to reinforce their domination upon the rest of the population, thus ensuring their power and the gradual abandonment of Imperial political structures.In 707, a Muslim fleet, under the command of Abd Allgaht ibn Musa, son of the governor of Ifriqiya, Musa ibn Nusayr, stopped off at the island.