**JOHN ALBERT, King of Poland.** — Third son of Casimir IV, King of Poland (b. 1459), he contended in 1490 with his elder brother Ladislaus, King of Bohemia, for the crown of Hungary, to which both had been summoned by opposing factions. Defeated and repelled, he consoled himself by obtaining, upon the death of his father (1492), the crown of Poland. At this time, the Florentine Filippo Buonaccorsi (Callimachus Experiens) exercised great influence over him, first as his tutor and now as his secretary.
Famous is the political program drafted by Callimachus for the King (*Consilium Callimachi*), inspired by concepts that might be called Machiavellian. At Callimachus’ advice, J. A. reconciled with his brother Ladislaus, establishing a harmonious domestic and foreign policy (Treaties of Buda, 1492, and Lewocza, 1494).
To implement the plan of transplanting the Polish administrative system into Wallachia by securing the cession of Prussia, in 1493 J. A. advanced into Moldavia to wrest from the Turks the ports of Kilia and Belgorod on the Black Sea and to subjugate the hospodar Stephen. The expedition ended in the destruction of the Polish army near Czerwiń and thus closed Polish ambitions toward the Black Sea. The absolutist program in domestic policy collapsed as early as 1496 at the Diet of Piotrków, where J. A., though relying on the *szlachta* (rural nobility), had to yield to the magnates at the expense of the Crown and the urban bourgeoisie. King J. A. died on 17 June 1501.
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**JOHN ANTONY OF MONTECUCCOLI:** *see VAZZI, JOHN ANTONY OF MONTECUCCOLI.*