Military defeats: Aside from the loss of the Banat and the temporary loss of Belgrade (1717–1739), the Ottoman border on the Danube and Sava remained stable during the eighteenth century. Russian expansion, however, presented a large and growing threat. Accordingly, King Charles XII of Sweden was welcomed as an ally in the Ottoman Empire following his defeat by the Russians at the Battle of Poltava of 1709 in central Ukraine (part of the Great Northern War of 1700–1721). Charles XII persuaded the Ottoman Sultan Ahmed III to declare war on Russia, which resulted in an Ottoman victory in the Pruth River Campaign of 1710–1711, in Moldavia. After the Austro-Turkish War, the Treaty of Passarowitz confirmed the loss of the Banat, Serbia, and “Little Walachia” (Oltenia) to Austria. The Treaty also revealed that the Ottoman Empire was on the defensive and unlikely to present any further aggression in Europe. The Austro-Russian–Turkish War (1735–1739), which was ended by the Treaty of Belgrade in 1739, resulted in the Ottoman recovery of northern Bosnia, Habsburg Serbia (including Belgrade), Oltenia and the southern parts of the Banat of Temeswar; but the Empire lost the port of Azov, north of the Crimean Peninsula, to the Russians. After this treaty the Ottoman Empire was able to enjoy a generation of peace, as Austria and Russia were forced to deal with the rise of Prussia. Educational and technological reforms came about, including the establishment of higher education institutions such as the Istanbul Technical University. In 1734 an artillery school was established to impart Western-style artillery methods, but the Islamic clergy successfully objected under the grounds of theodicy. In 1754 the artillery school was reopened on a semi-secret basis. In 1726, Ibrahim Muteferrika convinced the Grand Vizier Nevşehirli Damat Ibrahim Pasha, the Grand Mufti, and the clergy on the efficiency of the printing press, and Muteferrika was later granted by Sultan Ahmed III permission to publish non-religious books (despite opposition from some calligraphers and religious leaders). Muteferrika’s press published its first book in 1729 and, by 1743, issued 17 works in 23 volumes, each having between 500 and 1,000 copies.