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.
Turkish people
Under its founder, Osman I, the nomadic Ottoman beylik expanded along the Sakarya River and westward towards the Sea of Marmara. Thus, the population of western Asia Minor had largely become Turkish-speaking and Muslim in religion. It was under his son, Orhan I, who had attacked and conquered the important urban center of Bursa in 1326, proclaiming it as the Ottoman capital, that the Ottoman Empire developed considerably. In 1354, the Ottomans crossed into Europe and established a foothold on the Gallipoli Peninsula while at the same time pushing east and taking Ankara. Many Turks from Anatolia began to settle in the region abandoned by the inhabitants who had fled Thrace before the Ottoman invasion. However, the Byzantines were not the only ones to suffer from the Ottoman advancement for, in the mid-1330s, Orhan annexed the Turkish beylik of Karasi. This advancement was maintained by Murad I who more than tripled the territories under his direct rule, reaching some , evenly distributed in Europe and Asia Minor. Gains in Anatolia were matched by those in Europe; once the Ottoman forces took Edirne (Adrianople), which became the capital of the Ottoman Empire in 1365, they opened their way into Bulgaria and Macedonia in 1371 at the Battle of Maritsa. With the conquests of Thrace, Macedonia, and Bulgaria, significant numbers of Turkish emigrants settled in these regions. This form of Ottoman-Turkish colonization became a very effective method to consolidate their position and power in the Balkans. The settlers consisted of soldiers, nomads, farmers, artisans and merchants, dervishes, preachers and other religious functionaries, and administrative personnel.