Taking advantage of a civil war in neighbouring Russia, Sigismund invaded the country in 1609. In 1610, the Polish army and winged hussar units under the command of Hetman Stanisław Żółkiewski seized Moscow after defeating the Russians at the Battle of Klushino. The humiliated Vasili IV of Russia was caged and sent to Poland where he paid tribute in Warsaw and was later murdered in captivity. The Poles were eventually driven out of ruined Moscow after two years by a local uprising. Sigismund also countered the Ottoman Empire in the southeast; at Khotyn in 1621 the Commonwealth forces under Jan Karol Chodkiewicz achieved a decisive victory against the Turks. Their defeat and subsequent Janissary revolt marked the downfall of Sultan Osman II. Sigismund's liberal son, Ladislaus IV Vasa, successfully defended Poland's territorial possessions, but his death ended the centuries-long era of relative stability.