in 1359, Moldavia. The present-day fortress was constructed after 1400 by the Moldavian ruler Alexander the Good, with the help of Vytautas the Great of Lithuania. After 1433, it was occupied by Poland, due to wars between Alexander's successors, and was reconquered from the Poles by Stephen the Great of Moldavia in 1459 after a two-year siege. The fortress, strengthened by Stephen, during the 15th century, became the strongest on the northern border of the medieval Moldavia. Conquest by different states During Wallachian ruler Michael the Brave's conquest of Moldavia in May 1600, its ruler Ieremia Movilă took refuge in the Fortress of Khotyn together with his family, a handful of faithful boyars, and the former Transylvanian Prince, Sigismund Bathory. As the Moldavian state's power was weakened by that of the Ottoman Empire, the latter sought to gain control of the strategic river crossing. As a result, Hotin's later history was dominated by wars between the expanding Christian powers (first Poland, then Russia) and the expanding Ottoman Empire. The Turks suffered two decisive defeats at Khotyn in the 17th century, at the hands of the army of the Polish–Lithuanian Commonwealth: in 1621 by Hetman Jan Karol Chodkiewicz, and again in 1673 by Jan III Sobieski (see: Battles below). The Ottoman Empire finally seized the fortress from Moldavia in 1713 during the Great Northern War and held it during the following century as a base for its troops. Another power, Russian Empire, came to claim the region in the 18th century. The Turks amplified and enlarged the citadel, which was besieged and taken by the Russians on four occasions: in 1739 by Burkhard Christoph von Munnich, in 1769 by Prince Alexander Galitzine, in 1788 by Prince Josias of Coburg, and Ivan Saltykov, in 1807 by Ivan Ivanovich Michelson. With the start of the Russo-Turkish War in 1806, the Hotin Fortress was taken by the Imperial Russian Army and passed to Russia. With the signing of the Bucharest Peace Treaty in 1812, the entire region that became known as Bessarabia was annexed by the Russian Empire from Moldavia. From 1812 to 1918, Hotin was the administrative center of the Hotin County, one of the twelve, later nine counties of Bessarabia. During the 19th century, due to economic reasons and the Russian policy of colonization and russification, the Ukrainian population of Bessarabia (especially in its north) increased significantly, from around 15,000 in 1810