However , Carlos Hugo 's deviations from traditional Carlist ideology — most notably his endorsement of Titoist socialism — caused many Carlists to question his leadership . Carlos Hugo sought to change the political direction of the Carlist movement through the Carlist Party , of which he was the official head during the 1976 Carlist gathering when the fatal Montejurra incident occurred , and at which Sixtus Henry was also present , leading opposition to his brother 's reforms
Montejurra incident
Montejurra massacre
Prince Sixtus Henry of Bourbon-Parma