Additional factors for the uprising were the events in the middle of the 17th century, in particular the blow that the mighty Ottoman Empire received as the defeat at Vienna in 1683. The introduction of heavy taxes to secure funds for the expensive yet ineffective European campaigns of the empire and the deprivation of the Bulgarian Catholics of some of their rights played an important role in the setup of the uprising. Petar Parchevich, a highly educated Bulgarian Catholic cleric and diplomat, carried out a large-scale diplomatic campaign among the Christian rulers of Central Europe between 1630 and 1645. Together with Petar Bogdan and Franchesko Soymirovich, they visited Austrian monarch Ferdinand II, the king of the Polish–Lithuanian Commonwealth Sigismund III Vasa, and his heir, Władysław IV Vasa as well as Wallachian voivode, Matei Basarab. Around 1647 the Ottomans withdrew almost entirely from northwestern Bulgaria in relation to their war with Venice for Crete. Matei Basarab sent messengers to promise a 20,000-strong army to support the uprising. In the decisive moment, however, Władysław IV died on 20 May 1648 and the uprising was called off.