Mehmed II, also known as Mehmed the Conqueror, was a Turkish sultan in the 15th century who arrayed himself against Voivode Vlad III in an effort to get control of Ungro-Wallachia. Though repulsed on most occasions, he — through his proxy Radu the Handsome — was eventually successful in conquering the country and deposing Dracula, largely because of the prince's miscalculation.
When the Fifth Doctor, Peri and Erimem first arrived in Wallachia, they were briefly encamped with Mehmed's forces, who had effectively rescued them from Dracula's advancing armies. However, Radu intimated that the price for this protection would be that Erimem and Peri would have to enter Mehmed's harem and the Doctor would have to be the Sultan's court fool. The time travellers quickly decided to sneak away from the camp, but only Erimem was successful in the escape. (AUDIO: Son of the Dragon)