His Lordship The Count of Castelo Melhor
Secretary of State of the Kingdom of Portugal
In office 12 July 1662 – 9 September 1667
Monarch	Afonso VI
Preceded by	Gaspar Severim de Faria
Succeeded by	Manuel Pereira
Captain-Major of Santa Maria Island
In office 1667–1720
Monarchs	Afonso VI Peter II John V
Preceded by	Joana de Meneses
Succeeded by	Afonso de Vasconcelos
Personal details
Born	1636 Kingdom of Portugal
Died	1720 (aged 83–84) Santa Maria, Azores, Kingdom of Portugal
Military service
Allegiance	Kingdom of Portugal
Years of service	1657-1659
Battles/wars	Portuguese Restoration War

D. Luís de Vasconcelos e Sousa, 3rd Count of Castelo Melhor (1636 – 15 August 1720) was a Portuguese politician and prime minister.^[1]

Castelo Melhor was a Portuguese royal favourite who, as an effective governor of Portugal from 1662 to 1667 during the reign of Afonso VI,^[2] was responsible for the successful prosecution of the war against Spain, which led to Spanish recognition of Portugal's new ruling dynasty in 1668.^[3]

Shortly after Afonso VI's coming-of-age in 1662, Castelo Melhor saw an opportunity to gain power at court when the Afonso's mother, Queen-Regent Luisa, sent away one of the king's unruly favorites.^[4][5][6] Melhor managed to convince the angry king to take control of the throne and send his mother to a convent.^[2][4]

The King appointed Castelo Melhor his secret notary (escrivão da puridade), a position in which the favourite was able to exercise the functions of first minister.^[4][7]

Castelo Melhor overcame the difficulties which had hitherto beset Portugal in the war against Spain, reorganizing the troops (now reinforced by an English contingent by virtue of the English king Charles II's marriage to Catherine of Braganza) and entrusting their command to competent generals.^[8] Consequently, the Portuguese Restoration War entered a victorious phase for Portugal (1663–65) and Spain began peace negotiations.^[9][10]

Agreement proved difficult to attain and meanwhile the internal political situation in Portugal deteriorated.^[11] Castelo Melhor and his Francophile party were losing ground to the Anglophile party.^[12] The king was obliged to dismiss Castelo Melhor on 9 September 1667, in a palace coup organized by the king's wife Maria Francisca of Nemours and brother Pedro.^[4] Shortly afterwards, the king himself was also deprived of power.^[13]

Castelo Melhor went into exile in Paris^[10] and then London,^[14][15] but in 1685 he was permitted to return to Portugal and, two years after that, to court. On the accession of John V (1706), he was appointed a councillor of state and he continued to occupy a position of distinction until his death in 1720.

He was also the 12th captain-major of Santa Maria Island in the Azores from 1667 to 1720.

• Ames, Glenn Joseph (2000). Renascent Empire?: The House of Braganza and the Quest for Stability in Portuguese Monsoon Asia, ca. 1640-1683. Amsterdam: Amsterdam University Press. ISBN 9053563822.
• Birmingham, David (2003). A Concise History of Portugal. Cambridge University Press. pp. 50–51. ISBN 978-0-521-83004-1.
• de Faria, Ana Leal; Monteiro, Nuno Gonçalo (2021). Castelo Melhor e os Seus Tempos (1635-1720) (PDF) (in Portuguese). Centro de História da Universidade de Lisboa.
• Livermore, H.V. (1969). A New History of Portugal. Cambridge University Press. ISBN 9780521095716.
• Marques, Antonio Henrique R. de Oliveira (1976). History of Portugal. ISBN 978-0-231-08353-9.
• McMurdo, Edward (1889). The history of Portugal, from the Commencement of the Monarchy to the Reign of Alfonso III. London: Sampson Low, Marston, Searle, & Rivington. Retrieved 25 October 2023.
• Newitt, M. D. D (2005). A history of Portuguese Overseas Expansion, 1400-1668. New York: Routledge. Retrieved 25 October 2023.
• Stephens, H. Morse (1891). The Story of Portugal. New York: G. P. Putnam's Sons. Retrieved 25 October 2023.