A period of relative peace followed during the more prosperous and prestigious rule of Vasile Lupu. He took the throne as a boyar appointee in 1637 and began battling his rival Gheorghe Ștefan, as well as the Wallachian prince Matei Basarab. However, his invasion of Wallachia, with the backing of Cossack Hetman Bohdan Khmelnytsky, ended in disaster at the Battle of Finta in 1653. A few years later, Moldavia was occupied for two short intervals by the anti-Ottoman Wallachian prince Constantin Șerban, who clashed with the first ruler of the Ghica family, George Ghica. In the early 1680s, Moldavian troops under George Ducas intervened in right-bank Ukraine and assisted Mehmed IV in the Battle of Vienna, only to suffer the effects of the Great Turkish War.