Final answer:
The Swedish phase of the Thirty Years' War, led by Gustavus Adolphus, culminated in the Battle of Lützen but did not result in the Peace of Prague. The war eventually ended with the Peace of Westphalia in 1648.
Step-by-step explanation:
The Swedish phase of the Thirty Years' War spanned from 1629 to 1635 and indeed involved the leadership of King Gustavus Adolphus, who is known for his military skill and modernization of the Swedish army. This phase is historically noted for significantly aiding the Protestant cause against the Catholic Habsburgs. The Swedish phase culminated in the Battle of Lützen (1632), where Gustavus Adolphus was killed, marking a crucial point in the war. However, the Swedish phase did not result in the Peace of Prague; that peace treaty came later, in 1635, and was between the Emperor and various German states. Instead, the Thirty Years' War ended with the Peace of Westphalia in 1648, not with the conclusion of the Swedish phase.