When the Ottoman Turks began their conquest of further Balkan countries in the second half of the 14th century, they were opposed by Hungary, which came to known as the bastion of Christianity. The article analyses subsequent events of the 15th and 16th centuries when the term was first applied to the Kingdom of Poland. Poland’s greatest involvement in the war against the Muslims was during the reign of Ladislaus III of Hungary, who died in 1444 at the Battle of Varna. Under his successor, Kazimierz Jagiellończyk, Poland managed to avoid military conflict with Turkey, though it waged constant war with their allies, the Tatars. The first Turkish invasions of Poland followed the defeat in Bukovina in the autumn of 1497. In the ensuing decades...