Hamza Bey first appeared in 1421, when his brother,
Bayezid Pasha, tried unsuccessfully to stop
Mustafa Çelebi from taking
Edirne. Bayezid was of Albanian origin and a war captive. The 15th-century Byzantine historian
Doukas described Bayezid as a slave of
Albanian origin. Modern historian
Uzunçarşılı, without citing a source, wrote that he was born in
Amasya as the son of Amasyalı Yahşi Bey, earning him the epithet
Amasyalı, meaning "from Amasya," which implied he wasn't a convert or at least not a recent one. This means their grandfather was an Albanian convert to
Islam and joined the Ottoman conquest, settling in Amasya. Their troops defected to Mustafa, and Bayezid was executed; Hamza was spared because
Junayd of Aydın took pity on his youth. Hamza avenged his brother when he was appointed
Beylerbey of
Anatolia in 1424: he defeated Junayd, occupied his domains, seized Junayd and his family, and had them executed. Hamza Bey came to prominence, as a commander in
Murad II's fleet, during the
siege of Thessalonica, which in 1430 was ultimately successful. In 1453 Hamza Bey was made commander of the Ottoman fleet during the
Conquest of Constantinople; replacing
Suleiman Baltoghlu, when Baltoghlu failed to stop the escape of three Genoese galleys and a Byzantine ship through the Ottoman
blockade of the city. In the final assault on the city, in order to prevent defenders from the reinforcing the critical northern and western parts of the wall, Hamza and the Ottoman fleet was to provide diversionary attacks against the sea walls of
Constantinople in the south, on the
Sea of Marmara; and against the dam across
Golden Horn in the east. On the day of the assault, May 29, Hamza's forces were unable to force the
Byzantine defences, with those troops which managed to gain a foothold being easily repulsed. However, overall the
Ottoman assault was successful. Hamza Bey was to remain
Commander of the Ottoman fleet until 1456. After the capture of Constantinople, the Ottoman fleet was tasked with the conquest of the islands of the Aegean; and
Imbros,
Lemnos and
Thasos fell to the Ottomans. However, stalled by the
Knights of Rhodes, Hamza was unable to take the remainder of the Aegean, leaving Christian forces astride the Ottoman route from their new capital to the
Mediterranean proper. ==Death==