Béla adopted an active foreign policy soon after the withdrawal of the Mongols. In the second half of 1242 he invaded Austria and forced Duke Frederick II to surrender the three counties ceded to him during the Mongol invasion. On the other hand, Venice occupied Zadar in the summer of 1243. Béla renounced Zadar on 30 June 1244, but Venice acknowledged his claim to one third of the customs revenues of the Dalmatian town.