| Afonso VI | |
| Succession: | King of Portugal |
| Reign: | 6 November 1656 – 12 September 1683 |
| Cor-Type: | Acclamation |
| Coronation: | 15 November 1657 |
| Predecessor: | John IV |
| Successor: | Peter II |
| Reg-Type: | Regents |
| Regent: | Luisa de Guzmán (1656–1662) Peter, Duke of Beja (1668–1683) |
| Regent1: | Count of Castelo Melhor (1662–1667) |
| House: | Braganza |
| Father: | John IV of Portugal |
| Mother: | Luisa de Guzmán |
| Birth Date: | 21 August 1643 |
| Birth Place: | Ribeira Palace, Lisbon, Portugal |
| Death Date: | 12 September 1683 (aged 40) |
| Death Place: | Sintra Palace, Sintra, Portugal |
| Burial Place: | Pantheon of the Braganzas |
| Religion: | Roman Catholicism |
Dom Afonso VI (pronounced as /pt/; 21 August 164312 September 1683), known as "the Victorious" (Portuguese: o Vitorioso), was the second king of Portugal of the House of Braganza from 1656 until his death. He was initially under the regency of his mother, Luisa de Guzmán, until 1662, when he removed her to a convent and took power with the help of his favourite, D. Luís de Vasconcelos e Sousa, 3rd Count of Castelo Melhor.
Afonso's reign saw the end of the Restoration War (1640–68) and Spain's recognition of Portugal's independence. He also negotiated a French alliance through his marriage. In 1668, his brother Pedro II conspired to have him declared incapable of ruling, and took supreme de facto power as regent, although nominally Afonso was still sovereign. Queen Maria Francisca, Afonso's wife, received an annulment and subsequently married Pedro. Afonso spent the rest of his life and reign practically a prisoner.[1]
Afonso was the second of three sons born to King John IV and Queen Luisa. At the age of three, he experienced an illness that resulted in paralysis on the right side of his body. The condition was believed to have also affected his intellectual abilities. His father created him 10th Duke of Braganza.[2]
After the death of his eldest brother Teodósio, Prince of Brazil in 1653, Afonso became the heir apparent to the throne of the kingdom. He also received the crown-princely title 2nd Prince of Brazil.
He succeeded his father, John IV, in 1656 at the age of thirteen. His mother, Luisa de Guzmán, was named regent in his father's will.
Luisa's regency continued even after Afonso came of age because he was considered mentally unfit for governing. In addition to lacking intellect, the king exhibited wild and disruptive behavior. In 1662, after Afonso terrorized Lisbon at night alongside his favorites, Luisa and her council responded by banishing some of the king's companions that were associated with the raids. Angered, Afonso took power with the help of Castelo Melhor and Luisa's regency came to an end.[3] She subsequently retired to a convent,[4] where she died in 1666.
Afonso appointed Castelo Melhor as his private secretary (escrivão da puridade). He proved to be a competent minister. His astute military organization and sensible general appointments resulted in decisive military victories over the Spanish at Elvas (14 January 1659), Ameixial (8 June 1663) and Montes Claros (17 June 1665), culminating in the final Spanish recognition of sovereignty of Portugal's new ruling dynasty, the House of Braganza, on 13 February 1668 in the Treaty of Lisbon.
Colonial affairs saw the Dutch conquest of Jaffna, Portugal's last colony in Portuguese Ceylon (1658), and the cession of Bombay and Tangier to England (23 June 1661) as dowry for Afonso's sister, Infanta Catherine of Braganza, who had married King Charles II of England.
Melhor successfully arranged for Afonso to marry Maria Francisca of Savoy, a relative of the Duke of Savoy, in 1666, but the marriage was short-lived. Maria Francisca filed for an annulment in 1667 based on the impotence of the king. The church granted her the annulment, and she married Afonso's brother, Peter II, Duke of Beja.
Also in 1667, Pedro managed to gain enough support to force Afonso to relinquish control of the government to him, and he became prince regent in 1668. While Pedro never formally usurped the throne, Afonso was king in name only for the rest of his life.[5] For seven years after Peter's coup, Afonso was kept on the island of Terceira in the Azores. His health broken by this captivity, he was eventually permitted to return to the Portuguese mainland, but he remained powerless and kept under guard. At Sintra he died in 1683.[6]
The room where he was imprisoned is preserved at Sintra National Palace.