Carlos Hugo was the son of Xavier, Duke of Parma, and Madeleine de Bourbon-Busset and was baptized Hugues Marie Sixte Robert Louis Jean Georges Benoît Michel.

The movement split between the followers of Carlos Hugo and his socialist and liberal reforms and the traditionalists who rejected him including his younger brother Sixto Enrique who refused to accept him as king.

Among the terrorists were Stefano Delle Chiaie and members of the Argentine Anticommunist Alliance (Triple A), with logistic support from Francoist elements inside Spanish intelligence agencies and the Civil Guard.

That same day he issued a declaration certified by a Paris notary objecting to his name being used to legitimize a "grave doctrinal error within Carlism", and implicitly disowned the political line promoted by Carlos Hugo.

[7] In order to justify that declaration, Carlos Hugo alerted the police that his father had been abducted by Sixto, an accusation which was denied publicly by Don Javier himself, who had to be hospitalized heavily affected by the scandal generated.

[8] Shortly afterwards Don Javier issued another declaration, certified by a different Paris notary, confirming his oldest son as "my only political successor and head of Carlism".

[11] She repudiated and disinherited her children Carlos Hugo, María Teresa, Cecilia and Nieves, and ordered that upon her death they could not attend the wake for his corpse in the castle of Lignières.

[citation needed] Carlos Hugo and Irene were married on 29 April 1964, in the Borghese Chapel at the Basilica di Santa Maria Maggiore in Rome, by Cardinal Paolo Giobbe, the former Apostolic Nuncio to the Netherlands.