Gazi Husrev-beg (, Gāzī Ḫusrev Beğ; Modern Turkish: Gazi Hüsrev Bey; 1480–1541) was an Ottoman Bosnian sanjak-bey (governor) of the Sanjak of Bosnia in 1521–1525, 1526–1534, and 1536–1541. He was known for his successful conquests and campaigns to further Ottoman expansion into Croatia and Hungary. However, his most important legacy was major contribution to the improvement of the structural development of Sarajevo and its urban area. He ordered and financed construction of many important buildings there, and with his will bequeathed all his wealth into endowment for the construction and long-term support of religious and educational facilities and institutions, such as the Gazi Husrev-beg Mosque, and the Gazi Husrev-begova Medresa complex with a Gazi Husrev-beg Library, also known as Kuršumlija. Biography Origin Gazi Husrev-beg was born in Serres, Greece. His father, Ferhad-beg, was a Bosnian nobleman from Hum (modern-day Herzegovina), who worked as a high court official. His mother, Selçuk Sultan, was the daughter of the Sultan Bayezid II, making Gazi Husrev-beg Beyazid II's grandson. Career In less than three years, he conquered the fortresses of Knin, Skradin and Ostrovica. He was appointed sanjak-bey of the Sanjak of Bosnia on 15 September 1521, becoming one of Sultan Suleiman I's most trusted men. A relentless campaign of conquest followed soon; the fortified towns of Greben, Sokol, Jezero, Vinac, Vrbaški Grad, Livač, Kamatin, Bočac, Udbina, Vrana, Modruč, and Požega fell at his hands. He founded, among the many buildings he ordered to construct in the city, the vakuf of Sarajevo, which was active until the 20th century. Gazi Husrev-beg played a crucial role to overcome the Christian army at the Battle of Mohács. His 10,000 Akıncıs and his irregular cavalry, composed of Turks, Bosnians and Crimean Tatars, served as reserve soldiers in that battle. According to the Ottoman military strategy, the Akıncıs circled the European knights while the Turkish infantry made a counterfeit retreat after the first assault. Death Gazi Husrev-beg's forces struggled against a power vacuum in Montenegro after the death of Ottoman ally, islamized Montenegrin lord Skender-beg Crnojević in 1528. In 1541, during an uprising of Montenegro nobility, he set out to protect the Crnojevićs and the local populace. After fighting many battles to maintain order in the region, although finally victorious, he was killed while fighting Christian rebels in Mokro, a small village in Drobnjaci (present-day Montenegro). Legend states that he was a big man, so his warriors were