Peter II (Portuguese Pedro), the Pacific (April 26, 1648–December 9, 1706), Regent (1668–1683) and King of Portugal (1683–1706).

The second son of João IV, he was appointed regent for his insane brother, Afonso VI, in 1668, shortly after Spanish recognition of Portugal's independence. Peter first locked his brother away, but then came to the throne in his own right after Afonso's death in 1683. Around this time, the discovery of silver mines in Brazil enlarged Peter's treasury to the extent that he was able to dismiss the Cortes in 1697 and rule without its revenue grants for the rest of his reign.

Initially Peter supported France in the War of Spanish Succession (1702 - 1715), but on May 16, 1703, Portugal and Britain signed the famous Methuen Treaty. This trade accord granted mutual commercial privileges for Portuguese wine and English textile traders and would later give Britain huge clout in the Portuguese economy. This was followed in December 1703 by a military alliance between Portugal, Austria and Great Britain for an invasion of Spain. Portuguese and Allied forces had captured and then been expelled from Madrid.

Peter not only took his brother's throne but also his wife, Queen Marie-Françoise of Savoy. They had one daughter, Crown Princess Isabella Louise, aka "a Sempre-Noiva" (always engaged), because of her many marriage projects that were never completed. The Queen died shortly after Isabella's birth, and because the Princess was a fragile and sick child, the King decided to marry again. This time, the chosen was Maria Sophia, daughter of Phillip William of Neuburg. Among Sophia's sisters were Eleonor Madeleine, wife of Leopold I of Austria and Marianne, second wife of Charles II of Spain. This marriage was well succeeded, and they had another six children, including the new heir to the throne, John, who eventually succeeded his father after his death in 1706, as King John V of Portugal.