Which two kings fought at the Battle of Kressenbrunn according to the text?

Context: The Battle of Kressenbrunn was fought in July 1260 near Groissenbrunn in Lower Austria between the Kingdom of Bohemia and the Kingdom of Hungary for the possession of the duchies of Austria and Styria. The Bohemian forces were led by King Ottokar II Přemysl, while the Hungarians were led by his cousin, King Béla IV of Hungary.

In 1251, Ottokar's father King Wenceslaus I of Bohemia had not only granted him the title of a Margrave of Moravia, but also installed him as duke of Austria and Styria, territories that were princeless after the ruling Babenberg dynasty had become extinct in 1246. To legitimate his succession, Ottokar in 1252 married the Duchess Margaret of Austria, the sister of the last Babenberg duke and about 26 years his senior.

Answer: King Ottokar II and King Béla IV