On  August , at the battle of Mohács in south-western Hungary, Sultan Süleyman’s army of , to , men annihilated the badly organized and obsolete Hungarian royal army of , to , men. The battle of Mohács proved one of the most important events in European history of the early sixteenth century, since it led to the direct confrontation of the Ottomans and Habsburgs, the two superpowers of the time in East-Central Europe. King Louis II (–) of Hungary and Bohemia, along with most of the magnates and prelates of Hungary, perished in the battle. Although the sultan had withdrawn from Hungary by the autumn of , his victory and the death of the childless Louis II led to major geopolitical upheaval in the region. Hungary was at the time an elective monarchy, and the competing Hungarian noble factions could not agree on a successor to Louis II. They thus elected two kings: János (John) Szapolyai (r. –), Hungary’s richest aristocrat and royal governor (vajda) of Transylvania, and Ferdinand of Habsburg (r. –), archduke of Austria and younger brother of the Holy Roman Emperor Charles V (–). Szapolyai controlled the eastern parts of Hungary – with Ottoman military assistance – while Ferdinand ruled the country’s northern and western parts. Süleyman secured Ottoman influence over Hungary by stationing troops in southern Hungary and by supporting Szapolyai militarily against his Habsburg rival. When Szapolyai’s death ( or  July ) and Ferdinand’s military campaigns (October  and May-August ) to annex Szapolyai’s realms upset the military balance between the Habsburgs and the Ottomans, Süleyman occupied central Hungary and its capital city, Buda ( August ), which controlled the Danubian waterways leading to Central Europe.1 Buda became the centre of a newly established Ottoman province, the beylerbeyilik or vilayet of Budin, which remained the central Ottoman province in Hungary until it was reconquered by the Habsburgs in . Ferdinand’s attempt in  to expel the Ottomans from Buda ended in humiliation, and lack of adequate commitment of Habsburg resources in the s turned the country into the main continental battleground between the two major empires of the age, the Ottomans and the Habsburgs.