Wikipedia
Yanuka
Ban Yanuka ( Bulgarian: Бан Янука), defender of Sofia from Ottoman Turks in the late 14th century was the manager/deputy of the Tsar Ivan Shishman in Sredets. It is quite possible in the person of the "ban Yanko" /as a short Byzantine chronicle/in folk memory and epic to hide Transylvanian ruler John Hunyadi, who in December 1443 passed by combined Christian forces ravine near Dragoman, Sofia freeing of the Ottomans. Other authors (e.g. J. Andreev) identify it with Prince Ivan Asen brother Shishman.
Ban Yanuka was captured by the Turks in 1385, according to legend, after the betrayal.