King Afonso VI of Portugal reigned from 1656 to 1683. He became king at a young age after the death of his father, King John IV. His reign was marked by political instability and conflicts, including the Portuguese Restoration War against Spain. Due to health issues, Afonso VI was declared incapable of ruling, and his brother, Peter II, took over as regent. Afonso's reign ended in 1683 when he was deposed, and he spent the rest of his life in exile. His legacy includes the challenges of maintaining Portugal's independence during a tumultuous period in European history.