By the end of the 14th century, most of Anatolia was controlled by various Anatolian beyliks. Smyrna fell in 1330, and the last Byzantine stronghold in Anatolia, Philadelphia, fell in 1390. The Turkmen Beyliks were under the control of the Mongols, at least nominally, through declining Seljuk sultans. The Beyliks did not mint coins in the names of their own leaders while they remained under the suzerainty of the Mongol Ilkhanids. The Osmanli ruler Osman I was the first Turkish ruler who minted coins in his own name in 1320s; they bear the legend "Minted by Osman son of Ertugrul". Since the minting of coins was a prerogative accorded in Islamic practice only to a sovereign, it can be considered that the Osmanli, or Ottoman Turks, had become formally independent from the Mongol Khans.