Ottoman Empire
Several historians such as British historian Edward Gibbon and the Greek historian Dimitri Kitzikis have argued that after the fall of Constantinople, the Ottoman state took over the machinery of the Roman state, and that in essence the Ottoman Empire was a continuation of the Eastern Roman Empire under a thin Turkish Islamic guise. Kitzikis called the Ottoman state "a Greek-Turkish condominium". The American historian Speros Vryonis wrote that the Ottoman state was centered on "a Byzantine-Balkan base with a veneer of the Turkish language and the Islamic religion". Other historians have followed the lead of the Austrian historian Paul Wittek who emphasized the Islamic character of the Ottoman state, seeing the Ottoman state as a "Jihad state" dedicated to expanding the world of Islam. Another group of historians led by the Turkish historian M. Fuat Koprulu championed the ""gazi" thesis" that saw the Ottoman state as a continuation of the way of life of the nomadic Turkic tribes who had come from East Asia to Anatolia via Central Asia and the Middle East on a much larger scale, and argued that the most important cultural influences on the Ottoman state came from Persia. More recently, the American historian Heath Lowry called the Ottoman state a "predatory confederacy" led in equal parts by Turks and Greeks converted to Islam.
Territorial state
The Ottoman Empire had a centralized government in Istanbul which held power over the military, the provincial governors, and local religious leaders. In the Ottoman Empire, the military was controlled by the state, the lesser leaders of troops were all beholden to the Sultan, and in exchange, they were given territories to rule over. This tied the nobles to the central government. Because the elites handled most of the taxation and mustering of troops the Ottoman state was able to stay organized. Another critical feature of the Ottoman Empire is the freedom of religion; in the Empire, there was a system called the Millet system which gave non-Muslim religious communities autonomy to pick their rulers as long as they followed the laws and paid taxes. Also, local communities often were allowed to cling to certain customs, some were abolished, but the Sultan would leave many in place giving different provinces their own unique local cultures. These separate entities make the empire appear to be fragmented, but these policies served to unite the people, they were given enough freedom not to break away.