Afonso VI of Portugal was born in 1643 and became king at a young age after his father, John IV of Portugal, passed away. His reign began in 1656, but due to his health issues, his mother, Luisa de Gusmão, acted as regent for many years. Afonso VI is known for his struggles with mental health, which affected his ability to rule effectively. In 1667, Afonso VI was deposed by his brother, Peter II of Portugal, who took over the throne. Despite his challenges, Afonso VI's reign was marked by significant events, including the end of the Portuguese Restoration War and the signing of the Treaty of Lisbon in 1664.