Pedro de Sousa Holstein, 1st Duke of Palmela (1781-1850)
Sousa was born in the city of Turin, Italy. He was the son of Alexandre de Sousa Holstein, Conde de Sanfré (1751-1803), who served as Portuguese Ambassador in various European courts. Educated abroad, Sousa became an avid patron of the arts, and was involved in the Portuguese Academy in Rome. The family name Holstein descended from Sousa's paternal grandmother, Maria Anna Leopoldine, Princess of Schleswig-Holstein-Sonderburg-Beck, daughter of Friederich Wilhelm I, Duke of Schleswig-Holstein-Sonderburg-Beck, an area covering the northernmost region and southernmost region of Germany and Denmark, respectively.
As a young man, Sousa enlisted in the Portuguese army in 1796, and in 1802, he joined the foreign service, serving under Arthur Wellesley, 1st Duke of Wellington, in the Peninsular War. Like his father, Sousa became a Portuguese Ambassador to London and later attended Queen Victoria's coronation in 1838 as Ambassador Extraordinary. Following the 1820 Revolution in Portugal, Sousa became a leading liberal and cultural figure, acting as Secretary of State for Foreign Affairs. In 1823, he was made Marquis and appointed by King João VI to devise a new constitutional charter.
When Dom Miguel, son of King João, seized the throne in 1828, he condemned Sousa to death in absentia as he sided with the liberal opposition. Sousa fled to London where Dom Pedro, Emperor of Brazil, appointed him guardian to his daughter, Maria. Sousa acted as Maria's ambassador in London and established her regency on the island of Terceira in the Portuguese administered Azores. After a long military campaign, Dom Pedro was able to occupy Lisbon and subsequently reclaim the throne for his daughter Queen Maria II (r. 1834-1853). For his efforts and loyalty, Sousa was appointed the first Portuguese Prime Minister of the newly formed constitutional monarchy, serving from 1834-1835.
On 4 April 1836, Sousa was made 1st Duke of Faial by Queen Maria II, a title which was later changed to 1st Duke of Palmela on 18 October 1850, a few days after his death. His son, Domingos de Sousa Holstein (1818-1864) succeeded him as 2nd Duke of Palmela.