The fifteenth century marked a decisive moment in world history as the expansion of the Ottoman Empire into southeastern Europe posed a grave threat to Christianity. Amidst this turmoil, John Hunyadi rose to lead the struggle against the Islamic invaders. As voivode of Transylvania, and later royal governor and captain-general of Hungary, he became the principal defender of Christian Europe from 1441 until his death in 1456. This biography explores the life and times of John Hunyadi. It traces the history of the threat posed by the Ottoman Turks leading up to the great clashes of the fifteenth century and makes critical use of primary sources to tell the story of the man who directed the effort to defend Christian Europe against the Islamic onslaught. The author, Camil Mure?anu (1927-2015), was a distinguished historian from the University of Cluj-Napoca in Romania. He was a member of the Romanian Academy and director of the Institute of History in Cluj-Napoca. His study of the life and times of John Hunyadi is considered the most authoritative work on the subject.