Ottoman Hungary
Steinau served in the Bavarian contingent in the 1685–1688 campaign in Ottoman Hungary against the Ottoman Empire. He then participated in the War of the Grand Alliance against France under Charles V, Duke of Lorraine and in the successful siege of Mainz in 1689. Later he entered the service of the Republic of Venice in the 1695 war against the Ottoman Empire. In 1695–96 he was in the service of the Saxon elector Frederick August I (Augustus II the Strong, King of Poland) as the commander of the imperial troops in Royal Hungary in the continuous war with the Ottoman Turks.