Close to his brothers Edward, the future king of Portugal, and John, Lord of Reguengos de Monsaraz, Peter grew up in a calm environment free of intrigues.

On finishing a translation of Seneca's De Beneficiis in 1418, he initiated extensive travels throughout Europe, which would keep him away from Portugal for the next ten years.

After meeting with John II of Castile in Valladolid, he continued to Hungary, where he met with the Holy Roman Emperor Sigismund, and entered his service.

In 1425, Peter travelled to France and England and visited the universities of Paris and Oxford before arriving in Flanders in 1426, where he spent the next two years at the Burgundian court.

Later that year, King Henry VI of England (his first cousin once removed) made him a Knight of the Garter (as were already his father and older brother Edward).

In 1428, Peter visited his marquisate of Treviso and the nearby Republic of Venice, where he was presented with a copy of the book of Marco Polo by the doge.

He later gave that book, as well as maps of the Venetian trade routes in the Orient, to his younger brother Prince Henry the Navigator.

One of the maps was created by the famous Venetian cartographer Albertinus de Virga in 1411 and possibly shows North America before it was officially discovered.

With the death of Peter, Portugal fell under control of Afonso, Duke of Braganza, with a growing influence over the destiny of the country.

The cruel persecution of the Braganzas by John II was perhaps the response to the conspiracies that caused the fall of one of the major princes of the Ínclita Geração.