History of nationality in Cyprus  A "de facto" republic where Greek and Turkish Cypriots share many customs but maintain distinct identities based on religion, language, and close ties with their respective "motherlands", Cyprus is an island with a highly complex history of nationality due to its bi-communal nature and the ongoing conflict between the two groups. An internationally recognized region, Cyprus is partitioned into four main parts under effective control of the Republic of Cyprus, the Turkish Republic of Northern Cyprus (recognized only by Turkey), the UN-controlled Green Line, and British bases Akrotiri and Dhekelia respectively. Despite its history of conflict, the Green Line is now open and neighborly relationships are being fostered between the two groups. Being strategically located between three continents, Cyprus is a unique nation that did not follow the pattern of current European territories, and until this day the island serves as a bone of contention between the rival nationalisms of the Greek and the Turkish. Under the control of various powers throughout its ancient history, Cyprus was a Roman province from 58 BC to 395, after which it became part of the Byzantine Empire, then by Muslim Khalifate. Successively followed by periods of Lusignan (1192–1489), Venetian (1489–1571), and Ottoman rule (1571-1878), Great Britain eventually administered the region first under lease from the Sultan, and then upon annexation after the First World War with their colonial rule lasting until 1960. The millet system established during the period of Ottoman rule was an administrative system that served as a means of effectively reinforcing the divide between Turkish and Greek Cypriots. An administrative structure which distinguished the communities based on religion and ethnicity, each group was treated as a distinct entity. With the Orthodox Church playing a dominant position among the Greek Cypriots so as to help them preserve their ethnic, cultural, and political identity, religious activities and institutions factored into virtually every facet of the Cypriot community. Through the imposition of taxation and other various administrative tasks on a denominational basis, the millet system served as a central contributor in the creation of "political cleavage over ethnic lines. During the Ottoman period, a central supreme court in Nicosia was where the most significant criminal cases and appeals occurred. At the same time however, each district of the island (known as the five kaymakamliks) had their own separate systems in place which was presided over by the kaymakam, and represented both Muslim and Christian elected officials.