Gustavus Adolphus was the King of Sweden from 1611 to 1632. He is known for his military leadership and is often referred to as the "Father of Modern Warfare" for his innovative tactics and strategies. He played a significant role in the Thirty Years' War, leading the Protestant forces against the Catholic Habsburgs. Gustavus Adolphus is also remembered for his efforts to modernize the Swedish military and for his promotion of education and the arts. His reign had a lasting impact on Swedish history and European military tactics.