On 29 February 1528, King John I of Hungary received the support of the Ottoman Sultan. A three-sided conflict ensued as Ferdinand moved to assert his rule over as much of the Hungarian kingdom as he could. By 1529 the kingdom had been split into two parts: Habsburg Hungary and the "eastern-Kingdom of Hungary". At this time there were no Ottomans on Hungarian territories, except Srem's important castles. In 1532, Nikola Jurišić defended Kőszeg and stopped a powerful Ottoman army. By 1541, the fall of Buda marked a further division of Hungary into three areas. The country remained divided until the end of the 17th century.