The Moldavian Magnate Wars, or Moldavian Ventures, refer to the period at the end of the 16th century and the beginning of the 17th century when the magnates of the Polish–Lithuanian Commonwealth intervened in the affairs of Moldavia, clashing with the Habsburgs and the Ottoman Empire for domination and influence over the principality. The Magnate Wars (1593–1617) Causes Jan Zamoyski, Polish grand crown chancellor (kanclerz) and military commander (grand crown hetman), known for his opposition towards the Habsburgs, had been a vocal supporter of Commonwealth expansion in the southern direction. Since the early plans made by Commonwealth King Stefan Batory for the war against the Ottomans, Zamoyski supported them, viewing those plans as a good long-term strategy for the Commonwealth. Any policy that was against the Ottomans was also supported by the Holy See, and Pope Sixtus V strongly expressed his support for any war between the Commonwealth and the Ottomans. Three powerful magnate families from the Commonwealth, the Potockis, Koreckis and Wiśniowieckis, were related to the Moldavian Hospodar (Prince or Voivode) Ieremia Movilă (Jeremi Mohyła), and, after his death in 1606, they supported his descendants. Around the end of the 16th century, relations between the Commonwealth and the Ottomans, never too cordial, further worsened with the growing number of independent actions by Cossacks. From the second part of the 16th century, Cossacks started raiding the territories under Ottoman rule. The Commonwealth could not control the fiercely independent Cossacks, but was held responsible for them, since at that time they were nominally under the Commonwealth rule. At the same time, Tatars living under Ottoman rule were raiding the Commonwealth. However, they attacked mostly in the south-eastern areas of the Commonwealth, which were fairly sparsely inhabited, while the Cossacks were raiding the heart of the Ottoman Empire, wealthy merchant port cities just two days away from the mouth of the Dnieper river (which the Cossacks used as their main transportation route). By 1615, Cossacks had even burned the townships on the outskirts of Constantinople. Consecutive treaties between the Ottoman Empire and the Commonwealth called both parties to curb Cossack and Tatar activities, but they were never implemented on either side of the border. In internal agreements, pushed forward by the Polish side, the Cossacks agreed to burn their boats and stop their raiding. However, Cossack boats could be built quickly, and the Cossack lifestyle required periodic hunts for glory and booty.