In 1966, Prince Alfonso hired a Beverly Hills architect and, with the assistance of the Banus family, who were personal friends of dictator Francisco Franco and had already developed the later-controversial Valle de los Caídos, developed the high-end tourist resort Puerto Banus. The resort opened to much fanfare in 1970. Celebrities in attendance included Franco's designated successor, Juan Carlos (then Prince of Asturias), Prince Rainier of Monaco and his wife Grace Kelly, and Aga Khan IV; entertainers included Julio Iglesias. In 1973, exiled dictator Fulgencio Batista y Zaldívar, who had left Cuba with a fortune estimated at between $100 and $300 million and lived extravagantly in various Iberian resorts, died of a heart attack there. Fugitive financier Marc Rich bought a house in Marbella, renounced his American citizenship and claimed Spanish citizenship during his decades of evading American income taxes, although he spent more time in Switzerland, where he died.