Mehmed IV
Mehmed IV, also known as Dördüncü and Avci, (January 2, 1642 – 1693) was the sultan of the Ottoman Empire from 1648 to 1687. He was the son of Ibrahim I.
Known as Avci, the hunter, outdoor exercise took up much of the time of Sultan Mehmed. His reign is notable for a brief revival of Ottoman fortunes led by the ruthless Grand Vizier, Mehmed Köprülü. Köprülü regained the Aegean islands from Venice and fought successful campagns against Transylvania (1664) and Poland (1670–1674) — at one point Ottoman rule was close to extending into Podolia and the Ukraine.
A later vizier, Kara Mustafa was less able. Supporting the 1683 Hungarian uprising of Imre Thököly against Austrian rule, Kara Mustafa marched a vast army through Hungary and besieged Vienna (see Battle of Vienna). On the Khalenburg Heights, the Ottomans were utterly routed by the Imperial army (under Charles IV, Duke of Lorraine) and the vengeful Poles led by their King, John III Sobieski. Kara Mustafa was strangled in Belgrade on Mehmed's orders, but it was not enough to save the throne for the Sultan who was deposed and imprisoned at Edirne near his favourite hunting grounds.
The Osmanli Dynasty ruled the Ottoman Empire from 1281 to 1923, beginning with Osman I (not counting his father, Ertuğrul), though the dynasty was not proclaimed until 1383 when Murad I declared himself sultan. Before that the tribe/dynasty might have been known as Söğüt but was renamed Osmanli in honour of Osman.
The sultan was the sole regent and government of the empire, at least officially. The sultan enjoyed many titles such as Sovereign of the House of Osman, Sultan of Sultans, Khan of Khans, Commander of the Faithful and Successor of the Prophet of the Lord of the Universe. Note that the first rulers never called themselves sultans, but rather beys. See the article on state organisation of the Ottoman Empire for further information on the sultan and the structure of power.
Hereditiary heads of the House of Osman since 1926:
When Mehmed II (the Conquerer) took over Constantinople on May 29, 1453, he committed a coup d'état by replacing the
Emperor of the Roman empire (a.k.a. the Eastern Roman Empire a.k.a. Byzantine Empire) with himself. He took the title Emperor (imparator)and protector of Orthodox Christianity.
He let himself be crowned Emperor by the Patriarch of Constantinople Gennadius Scholarius, whom he protected and whose stature he elevated into leader of all the Eastern Orthodox Christians.
So in addition to being Sultan of the Muslim citisens and Khan of the Turks, he was now also styled Emperor of the Romans.
As emperor of the Romans he laid claim to all the Roman territories and succesfully managed to put most of the Roman territories (except Rome and Italy) under his own control.
