The Ottoman – Habsburg wars were fought from 16th through 18th century between the Ottoman Empire and the Habsburg (later Austrian) Empire, which was at times supported by the Holy Roman Empire, Kingdom of Hungary and Habsburg Spain. The wars were dominated by land campaigns in Hungary and Croatia.
By the 16th century, the Ottomans had become a serious threat to Europe, with Ottoman Barbary ships sweeping away Venetian possessions in the Aegean and Ionia. The Protestant Reformation, the France–Habsburg rivalry and the numerous civil conflicts of the Holy Roman Empire served as distractions. Meanwhile the Ottomans had to contend with the Persian Safavid Empire and to a lesser extent the Mamluke Sultanate, which was defeated and fully incorporated into the empire.
Initially, Ottoman conquests in Europe made significant gains with a decisive victory at Mohács reducing around one third (central) part of Kingdom of Hungary to the status of an Ottoman tributary. Later, the Peace of Westphalia and the Spanish War of Succession in the 17th and 18th centuries respectively left the Austrian Empire as the sole firm possession of the House of Habsburg. By then, however, European advances in guns and military tactics outweighed the skill and resources of the Ottomans and their elite Janissaries, enabling the Habsburgs to retake Hungary. The Great Turkish War ended with three decisive Holy League victories at Vienna, Mohács and Zenta. The wars came to an end following Austria’s disappointing performance in the war of 1787-1791, which Austria fought in alliance with Russia. Intermittent tension between Austria and the Ottoman Empire continued throughout the nineteenth century, but they never again fought each other in a war and ultimately found themselves allied in World War I, in the aftermath of which both empires were dissolved.