Background
He was the youngest son of John IV and was created Duke of Beja. Following his father"s death his mother became regent for the new king Afonso VI, Peter"s elder, partially paralysed and mentally unstable brother. In 1662 Afonso put away his mother and assumed control of the state.
Career
He was sometimes known as o Pacífico, "the Peaceful". Peter thereupon inherited the throne. Around this time, the discovery of gold mines in the Portuguese colony of 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.
He was tall, well proportioned, with dark eyes and dark hair.
Peter initially supported France and Spain in the War of Spanish Succession (1701–1714), but on 16 May 1703, Portugal and Great Britain signed the Methuen Treaty. This trade accord granted mutual commercial privileges for Portuguese wine and English textile traders and would later give Britain significant influence 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, under the command of the Marquês das Minas, captured Madrid in 1706, during the campaign which ended in the Allied defeat at Almansa.