This has got to be the longest title ever. It should go in the Guiness Book of World Records. I am sure the man himself couldn’t have realed out the full title correctly!
Let all those who puff up their chest and cling to titles beware – read this title and despair!

His Imperial Majesty The Sultan Süleyman I, Sovereign of the Imperial House of Osman, Sultan of Sultans, Khan of Khans, Commander of the Faithful and Successor of the Prophet of the Lord of the Universe, Protector of the Holy Cities of Mecca, Medina and Jerusalem, Emperor of The Three Cities of Constantinople, Andrinopole and Bursa, and of the Cities of Damascus and Cairo, of all Armenia, of the Magris, of Barka, of Kairuan, of Aleppo, of Arabic Iraq and of Ajim, of Basra, of El Hasa, of Dilen, of Raka, of Mosul, of Parthia, of Diyarbakır, of Cilicia, of the Vilayets of Erzurum, of Sivas, of Adana, of Karaman, Van, of Barbary, of Abyssinia, of Tunisia, of Tripoli, of Damascus, of Cyprus, of Rhodes, of Candia, of the Vilayet of the Morea, of the Marmara Sea, the Black Sea and also its coasts, of Anatolia, of Rumelia, Baghdad, Kurdistan, Greece, Turkistan, Tartary, Circassia, of the two regions of Kabarda, of Georgia, of the plain of Kypshak, of the whole country of the Tartars, of Kefa and of all the neighbouring countries, of Bosnia and its dependencies, of the City and Fort of Belgrade, of the Vilayet of Serbia, with all the castles, forts and cities, of all Albania, of all Iflak and Bogdania, as well as all the dependencies and borders, and many other countries and cities.

Excerpt above is from the article of the same title on wikipedia.