Gjergj Kastrioti, commonly known as Skanderbeg, was an Albanian feudal lord and military commander who led a rebellion against the Ottoman Empire in what is today Albania, North Macedonia, Greece, Kosovo, Montenegro, and Serbia.

A member of the noble Kastrioti family, Skanderbeg was sent as a hostage to the Ottoman court. He graduated from the Enderun School and entered the service of the Ottoman sultan Murad II (r. 1421-1444) for the next twenty years. His rise through the ranks culminated in his appointment as sanjakbey of the Sanjak of Dibra in 1440. During the Battle of Nish in 1443, he deserted the Ottomans and became the ruler of Krujë and nearby areas extending from Petrelë to Modrič. In March 1444, he established the League of Lezhë, with support from local noblemen, and unified the Albanian principalities.

In 1451, through the Treaty of Gaeta, Skanderbeg recognized de jure the sovereignty of the Kingdom of Naples over Albania, ensuring a protective alliance, although he remained a de facto independent ruler. In 1460-61, he supported Ferdinand I of Naples (r. 1458-1494) in his wars and led an Italian expedition against John II of Anjou (r. 1453-1470). In 1463, he was earmarked to be the chief commander of the crusading forces of Pope Pius II, but the Pope died while the armies were still gathering and the greater European crusade never took place. Together with Venetians, he fought against the Ottomans during the First Ottoman-Venetian War (1463-1479) until his death.

Skanderbeg ranks high in the military history of that time as the most persistent-and ever-victorious-opponent of the Ottoman Empire during its heyday. He became a central figure in the Albanian National Awakening of the 19th century. He is honored in modern Albania and is commemorated with many monuments and cultural works. Skanderbeg's military skills presented a major obstacle to Ottoman expansion, and many in Western Europe considered him to be a model of Christian resistance against the Ottomans.