Mother Courage takes place against the backdrop of the Thirty Years' War. The Thirty Years' War was a war that went through many different phases. The conflict started out as a religious dispute between Protestant and Catholic countries, but alliances changed throughout the war, mixing Catholics and Protestants on both sides as the conflict became more about money and territory and less about religion. The conflict began in 1618—when Protestants revolted against Catholics in Bohemia and famously threw two officials out a window—and concluded in 1648 with a treaty. In addition to its length, the Thirty Years' War is infamous for its bloodiness. Estimates of the death toll range from 4.5 to 8 million.
The play itself begins in the Spring of 1624, in a town within the Swedish county of Dalarna. After the Swedish army—which is fighting on the Protestant side—recruits Mother Courage's sons, Mother Courage joins their baggage train and journeys with them throughout Poland. She follows the Swedish army for a total of five years, before the Catholics take her prisoner. When they capture her, they do not imprison her. Instead, Mother Courage simply joins their wagon train and follows them on their campaign throughout Europe. Later, she rejoins the Protestants. Who Mother Courage follows and whose money she takes doesn't matter to her, her principles are guided by profit, not by ethics.
Brecht chooses to forgo a consistent setting and keep his character constantly on the move to show how war and capitalism both displace people. War leaves a wake of destruction wherever it goes, displacing people from their homes as it turns towns into battlefields. Since Mother Courage’s source of profit constantly migrates, she has to follow the war itself to make money for her business. Thus, both her life circumstances and her greed keep her from settling down to make a home.