After seven years of war and the failed Siege of Vienna in 1529, the Treaty of Constantinople was signed, in which John Szapolyai was recognized by the Austrians as King of Hungary as an Ottoman vassal, and the Ottomans recognized Habsburg rule over Royal Hungary. Very badly prepared, the siege came to nothing, and the starving allied army which operated in devastated territories, had to withdraw. They were pursued by an Ottoman relief army led by border commanders and attacked near Đakovo and Valpovo on the Drava river. Katzianer fled with the cavalry and abandoned his army to be annihilated.