The navy of the Fatimid Caliphate (909–1171) was one of the most developed early Muslim navies and a major force in the central and eastern Mediterranean in the 10th–12th centuries. As with the state it served, its history can be distinguished into two phases. The first period, from c. 909 to 972, when the Fatimids were based in Ifriqiya (modern Tunisia), and the second period, lasting until the end of the dynasty in 1171, when the Fatimids were based in Egypt. During the first period, the navy was employed mainly in the constant warfare with the Byzantine Empire in Sicily and southern Italy, where the Fatimids enjoyed mixed success, as well as in the initially unsuccessful attempts to conquer Egypt from the Abbasids and the brief clashes with the Umayyad Caliphate of Córdoba. During the first decades after the conquest of Egypt, the main enemy remained the Byzantines, but the war was fought mostly on land over control of Syria, and naval operations were mostly limited to maintaining Fatimid control over the coastal cities of the Levant. Warfare with the Byzantines ended after 1000 with a series of truces, and the navy became once more important with the arrival of the Crusaders in the Holy Land in the late 1090s. Despite it being well funded and equipped, and one of the few standing navies of its time, a combination of technological and strategic factors prohibited the Fatimid navy from being able to secure supremacy at sea, or interdict the Crusaders' maritime lines of communication to Western Europe. The Fatimids retained a sizeable navy almost up to the end of the regime, but most of the fleet, and its great arsenal, went up in flames in the destruction of Fustat in 1169.