Alfonso's renunciation of his rights as heir to the Spanish throne in order to marry Cuban commoner Edelmira Sampedro caused controversy at the time.

A similar situation would take place three years later in Britain with his second cousin Edward VIII, who would abdicate as King of the United Kingdom and Emperor of India to marry an American divorcee, Wallis Simpson.

Though appearing to have sustained minor injuries, his haemophilia, inherited through his great-grandmother Queen Victoria, led to fatal internal bleeding.

As decreed by custom, he was registered by the Marquis of Figueroa, Minister of Justice, in the Civil Registry of the Royal Family as Alfonso Pío Cristino Eduardo Francisco Guillermo Carlos Enrique Eugenio Fernando Antonio Venancio.

His godparents were his paternal grandmother, Queen Maria Cristina, and Pope Pius X, who was represented by Aristide Cardinal Rinaldini.

[4] The car crashed into a telephone booth and Alfonso appeared to have only minor injuries, but his haemophilia led to fatal internal bleeding.

Alfonso’s youngest brother, Gonzalo, had died just over four years before under very similar circumstances—having also inherited hemophilia, he was involved in a crash after the automobile he was in swerved to avoid a cyclist.