Barbaros quickly proceeded to strengthen and build the Ottoman Navy, to the extent that the Imperial Navy was on par with all Mediterranean countries.] In 1535, Karl V won Tunis, a city Important maintenance of the Ottoman Army. In this classroom we are flamingos poster. In 1536, the war with the Republic of Venice broke out, causing Suleiman I to accept an alliance with King François I of France to fight against Karl V. In 1538, Barbaros Hayreddin defeated the Spanish navy in battle. Beatle at Preveza. The victories at Preveza (1538) and Djerba (1565) then caused the Ottoman Empire to maintain the Mediterranean domination for 33 years until the Battle of Lepanto in 1571.