– Cadiz, 1666) was the older son of George of Lencastre, 1st Duke of Torres Novas, and grandson of Álvaro and Juliana of Lencastre, 3rd Dukes of Aveiro.

However, after 1659, he fled to Brest, in Brittany, and from there he travelled to Spain, where he supported the Spanish Habsburgs rights to the throne of Portugal.

He was quite welcomed in Madrid by King Philip IV of Spain, who granted him the new Spanish title of Duke of Ciudad Real, but, in spite his mother and sister also lived in Madrid, he didn't feel comfortable among the conservative Spanish nobility.

Meanwhile, in Portugal, Dom Raimundo of Lencastre was condemn for treason (in 1663) and the King of Portugal, John IV, confiscated the Dukedom and granted it to Raimundo's uncle, Peter of Lencastre, a Braganza supporter, who was recognised as 5th Duke of Aveiro and 5th Marquis of Torres Novas.

In 1665, the Spanish tried a last effort to conquer Portugal and Dom Raimundo advised a simultaneous naval expedition, leaving from Cadiz, against the Portuguese cost, which he led.