Along with her rather long name, she held more than 50 aristocratic titles, among them the Duchy of Berwick.
Estimates for her fortune run as high as 3.5 billion ($5.6 billion). But the Duchess was equally famous for her individualism - following her last of three weddings, in 2011, to a civil servant 25 years her junior, she kicked off her shoes and did some flamenco dancing.
Her family home in Madrid, the Liria Palace, reportedly contained 249 oil paintings, including works by El Greco, Rubens and Rembrandt. The Duchess' collection of historical documents, meanwhile, included letters written by Christopher Columbus and a first edition of Don Quixote.
Physically striking, with frizzy white hair, the Duchess, born in 1926, paid scant attention to the repressive social mores that predominated in the Franco era. A fixture in the international jet set, she not only learnt to speak five languages and travelled extensively, but was also a fan of bullfighting and flamenco.
Equally individual in her dress sense; even in her 80s she was not averse to wearing fishnet tights. Refusing to pose nude for Picasso was one of her few concessions to the norms of the era.
Her social life was never short of drama, either, right up to 2011 when she ignored her children's initial opposition, and married Alfonso Diez, 25 years her junior. Her first marriage, in 1947 to the son of the Duke of Sotomayor, has been described as Spain's last great feudal wedding - the young Duchess wore jewels worth 1.2 million in front of 1000 guests. Her second was to a former Jesuit priest.
Rumours about the protocol implications of her numerous titles - she was a duchess five times over, once a countess-duchess, 18 times a marchioness, 18 times a countess and once a viscountess - flourished. She was allowed, it was said, to enter Seville cathedral on horseback, did not have to kneel to the Pope and Britain's Queen Elizabeth was supposed to curtsy to her. This rumour persisted even after she rubbished the story, and bowed to the Queen, in 1988.
In later years, news of the Duchess increasingly centred round her health problems, but right up to the end she never seemed troubled by the press' constant fascination with her. As she told one gossip magazine, "If they forget you, you're nobody."
- Independent