Born Sefë Mahmuti sometime around 1825 in the village of Koshare near Ferizaj, Kosharja was recruited into the ranks of the Ottoman army at around 1855, serving for a total of 5 years.

[1] Sefë Kosharja was one of the most notable figures of the League of Prizren, an Albanian political organisation that sought to create an independent Albania, free from the Ottomans, South Slavs, and the Greeks.

Along with several other artillerymen, Sefë built two catapults that hit Dervish Pasha's army from behind, enabling fighters like Mic Sokoli to attack the positions of the Ottoman cannons.

He was captured alive by the Ottoman Turks and a military trial led by Dervish Pasha quickly sentenced him to death; he was hung on a tree.

During the night, three days past his hanging, his nephews - Asllan and Shaban Emini from the neighbourhood of Hysiqi in Shtime - removed his body from the rope and buried their uncle in a secret location.