Alfonso Cabeza de Vaca y Leighton, 17th Marquis de Portago came from an aristocratic and wealthy background. "Fon" de Portago was born in London but grew up in France, in the chic seaside resort of Biarritz, while his father fought with General Franco in the Spanish Civil War. His mother came from Ireland and was the widow of a wealthy financier.
De Portago grew up surrounded by money. He was a great sportsman in his youth, fencing, playing polo, riding and even flying. When he was still in his teens he won a $500 bet by flying an airplane under a bridge. Later he became a member of the Spanish Olympic bobsleigh team and a very successful jockey in French steeplechasing. He took part in Britain's most famous horse race - the Grand National - on two occasions.
In 1953 he attended the New York Motor Show and met the American Ferrari importer Luigi Chinetti, a former winner of the Le Mans 24 Hours. Chinetti asked him if he would like to be his co-driver on the Carerra Panamericana through Mexico and de Portago agreed. He later bought a Ferrari sportscar and made his racing debut in the Buenos Aires 1000 in 1954, partnered by Harry Schell. They finished second. He then bought a Maserati sportscar and raced with some success in Europe.
For the 1955 season Enzo Ferrari sold him a Formula 1 car but De Portago destroyed this in the International Trophy race at Silverstone, breaking a leg badly in the accident. Success in sportscar racing at the end of the year resulted in Ferrari hiring him as the fifth Ferrari factory driver in 1956 alongside Fangio, Collins, Musso and Castellotti. His best finish was a shared second at the British GP when he handed his car over to Collins. He finished fifth in Argentina in January 1957 but a week before the Monaco GP his car suffered a tire failure in the village of Guidizzolo in the closing stages of the Mille Miglia.
De Portago, his co-driver Edmund Nelson and 10 spectators - five of them children - were killed. Twenty more people were injured. Enzo Ferrari spent four years fighting manslaughter charges as a result of the crash, which also ended the history of the Mille Miglia.
from http://www.grandprix.com encyclopedia