Emirate of Sicily conquer Castrogiovanni (the modern Enna, where Euphemius died) and retreated back to Mazara. In 830 they received a strong reinforcement of 30,000 Ifriqiyan and Andalusian troops. The Iberian Muslims defeated the Byzantine commander Teodotus in July–August of that year, but again a plague forced them to return to Mazara and then to Ifriqiya. The Ifriqiyan units sent to besiege Palermo managed to capture it after a year long siege in September 831. Palermo became the Muslim capital of Sicily, renamed al-Madinah ("The City"). The conquest was a see-saw affair; with considerable resistance and many internal struggles, it took over a
Capital city meaning "head". In several English-speaking states, the terms county town and county seat are also used in lower subdivisions. In some unitary states, subnational capitals may be known as "administrative centres". The capital is often the largest city of its constituent, though not always. Historically, the major economic centre of a state or region often becomes the focal point of political power, and becomes a capital through conquest or federation. (The modern capital city has, however, not always existed: in medieval Western Europe, an itinerant (wandering) government was common.) Examples are Ancient Babylon, Abbasid Baghdad, Ancient Athens, Rome, Constantinople, Chang'an,