The date of Dragutin's marriage with Catherine of Hungary is also unknown. His father and her grandfather, Béla IV of Hungary, most probably arranged the marriage during the peace negotiations that followed Uroš I's invasion of Mačva in 1268, but an earlier date cannot be excluded. Mačva was a Hungarian border province to the north of Serbia which had been governed by Béla IV's daughter, Anna, on behalf of her minor son, Béla. Uroš I launched a plundering raid against the province, but he was captured and forced to seek a reconciliation. Catherine's father, Stephen V, had been bearing the title of "younger king" as his father's co-ruler and heir and the same title was bestowed on Dragutin in recognition of his exclusive right to inherit Serbia from his father. The Peace of Pressburg between Stephen V and King Ottokar II of Bohemia is the oldest extant document which describes Dragutin as a "younger king".