The Polish–Swedish War (1617–18) was a phase of the longer Polish–Swedish War (1600–29). It continued the war of 1600–11 and was an attempt by Sweden to take Polish pressure off Russia. The Polish–Lithuanian Commonwealth was then also fighting Tartars and (on the southern front) the Ottoman Empire. Russia and Sweden were at that stage allied, prior to the Ingrian War, part of Russia's Time of Troubles. The 1617–18 war's cause was a dispute over Livonia and Estonia, and a dispute between Sigismund III Vasa and Gustavus Adolphus over the Swedish throne.