 During World War II and the Post-War period, the area's royal affiliations intensified, as many heads of European royal houses and deposed monarchs, including King Edward VIII of the United Kingdom, King Juan Carlos I of Spain, and King Umberto II of Italy made their home in Cascais and Estoril, finding refuge in Portugal's neutrality in the war or from tense political situations in their own countries.Due to its concentration of high-profile personalities, the riviera became a center of espionage during WWII, inspiring author Ian Fleming in his creation of the "James Bond" series.Sintra had been a royal retreat since the Portuguese Renaissance in the 15th century, but it was in the 19th century, when King Fernando II of Portugal decided to build his summer retreat, Pena Palace, in the Sintra Mountains overlooking the Atlantic Ocean, that it became both the center of the Romanticist movement in Portugal and the summer residence of the Portuguese nobility.