[citation needed] Gaetan was a member of the House of Bourbon-Two Sicilies and consort to Isabella, Princess of Asturias, twice the recognized heir presumptive to the throne of Spain.

The ceremony took place shortly before Spain's Glorious Revolution which brought an end to Isabella II's reign.

For two years, Gaetan traveled throughout Europe visiting relatives in major cities including Vienna.

[citation needed] In the course of his short life Gaetan pursued an active military career, including commissions in the Bourbon Neapolitan army and subsequently, in exile, as colonel of a regiment of lancers in Austria.

During the 1868 revolution against Queen Isabella II of Spain, the Prince, aged only 22, commanded the Pavia Hussars regiment and fought at the Battle of Alcolea.