The history of Kassa was heavily influenced by the dynastic disputes over the Hungarian throne. Together with the decline of the continental trade brought the city into stagnation. Vladislaus III of Varna failed to capture the city in 1441. John Jiskra's mercenaries from Bohemia defeated Tamás Székely's Hungarian army in 1449. John I Albert, Prince of Poland, could not capture the city during a six-month-long siege in 1491. In 1526, the city homaged for Ferdinand I, Holy Roman Emperor. John Zápolya captured the town in 1536 but Ferdinand I reconquered the city in 1551. In 1554, the settlement became the seat of the Captaincy of Upper Hungary.