Philip III of Spain was born on April 14, 1578, and became king in 1598 after the death of his father, Philip II of Spain. His reign lasted until 1621 and is often characterized by a focus on peace and diplomacy, particularly through the signing of the Treaty of London in 1604, which ended hostilities with England. During his rule, Philip III delegated much of the governance to his favorite, the Duke of Lerma, leading to a decline in royal authority. His reign also saw the continuation of Spain's involvement in the Thirty Years' War, which would have lasting effects on the Spanish Empire.