Mehmed II
Mehmed continued his conquests in Anatolia with its reunification and in Southeast Europe as far west as Bosnia. After conquering Constantinople and getting the Byzantines out of the way, he started making more conquests in the Balkans and focused on his Balkan campaigns, even unsuccessfully laying siege to Belgrade in 1456 at one point. He was also known for his rivalry with Vlad the Impaler, who grew up at his father's court alongside him. Vlad the Impaler had taken control over Wallachia and rebelled against the Ottoman Empire, thus Mehmed II sent an Ottoman army, resulting in a war between the two. The war ended when Vlad was killed by an Ottoman patrol in Wallachia. He was then beheaded with some saying his head was sent to Mehmed II himself at the capital city Constantinople (modern Istanbul) by the Ottoman soldiers. He was also known for his campaigns against Albanian rebel leader Skanderbeg. For most of his reign, Mehmed II was on campaign against either John Hunyadi, Vlad the Impaler or Skanderbeg. Domestically, he made many political and social reforms, encouraged the arts and sciences, and by the end of his reign, his rebuilding program had changed Constantinople into a thriving imperial capital. He is considered a hero in modern-day Turkey and parts of the wider Muslim world. Among other things, Istanbul's Fatih district, Fatih Sultan Mehmet Bridge and Fatih Mosque are named after him.