Having signed the Treaty of Stolbovo ending their Ingrian War with Russia in 1617, the Swedes under king Gustav II Adolf (Gustavus Adolphus, hailed as savior of Protestant Europe) had expanded their gains in their previous war with the Polish-Lithuanian Commonwealth, in the disputed Livonia region, taking Dünamünde and Pernau in 1617.
When the truce from that war expires in November 1620, Gustav Adolf succeeds in taking the city of Riga after a few weeks of siege.
