Each of the two separate realms had a mission of its own, and with great difficulty Poland was forced to ascertain the price of political community with the only half-christianised Lithuania and Hungary to find the means of providing for her own military and political true needs, in the time of Sigismund, an emperor, a restorer of the catholic unity, a peace-maker between France and England, without feeling the lacks of him as a sovereign at home. Both stood unprepared, in the welter of the decay of the Middle Ages, before the Ottoman Turks, who united the strenght of Mongolian rule with the Byzantine ideals of domination.
Notwithstanding the energetic attitude of the King-Emperor against the Hussites, forced, before the onslaught of the friars of Jacob della Marchia, to seek a refuge in Moldavia where their gospel was translated into the popular tongue; notwithstanding his plans for introducing the Teutons in Licostomo-Chilia, on the Danube, and Severin, the work of catholic propaganda was left to the free-lance Franciscans. Their tireless little army made Transylvania its headquarters, when an extraordinary personality had now arisen to lead the « poor of Christ» not only against these heretics, but against the formidable armies of Mahomet the Second. As the Sultan endeavoured at Belgrade to gain the door to Hungary and the Christian Occident, so he encountered the Calabrian saint with his band of adventurers and beggars, of mystics and mendicants who fought in the holy name of Christ, neither giving nor asking quarter and winning the most unexpected victories. The new St. John, leader of both Hungarians and Roumanians, had as principal helper the Roumanian of Transylvania, John Hunyadi. For more than ten years this knight of eastern Christianity, later, in the service of a child of foreign origin, the ruler of the Hungarian realm of which he was the
