Many of Xavier's uncles and aunts came from European royal or ducal families,[3] though the only one actually ruling was his mother's sister, Infanta Maria Ana of Portugal, Grand Duchess of Luxembourg.

Though catering to Catholic aristocracy from all over Europe, the school offered Spartan conditions; when later enquired how he survived the Nazi concentration camp, prince Xavier joked: "I attended the Stella.

[51] Exact details of his service are not clear; what was left of the pre-war Belgian army served on a relatively calm sector of the frontline in Flanders and France, next to the English Channel.

In 1919 together with Sixte he travelled to England and contacted king George V; the British support materialized as a liaison officer, dispatched to the republican Austria to assist the unhappy couple on their route to exile.

As a counter-measure, they decided to challenge the French state, which in 1915 seized Chambord as property of Élie, the Austrian officer; the Versailles Treaty stipulations allowed to conclude the seizure legally if combined with paying compensation fee.

Scholars speculate that it was prince Xavier’s legitimism, Christian spirit, modesty, impartiality and lack of political ambitions which prompted Alfonso Carlos to appoint him as a future regent.

Don Javier, in the late summer watching the events unfold from Sant-Jean-de-Luz, was supervising increasing Carlist military effort,[96] yet was unable to engage in discussion with the generals.

[100] Following the Unification Decree he entered Spain in May; sporting a requeté general's uniform, and in apparent challenge to Franco he toured the front lines,[101] lifting Carlist spirits.

[103] Following another brief visit and another expulsion in late 1937,[104] Don Javier aimed at safeguarding Carlist political identity against the unification attempts, though he refrained also from burning all bridges with the emerging Francoist regime.

Some scholars claim he served as an intermediary, trusted by the British royal family,[114] including King George VI, and by Pétain;[115] as he did not leave France, it seems that he wrote letters which provided credibility for the envoys sent.

At one point[120] he joined works of the Comité d'Aide aux Réfractaires du STO and welcomed labor camp escapees in wooden areas of his estates, providing basic logistics and setting up shelters for the sick in his library.

[142] Don Javier and Fal stuck to rigorous discipline and dismissed Sivatte from Catalan jefatura,[143] though they also tried to reinvigorate Carlism by permitting individual participation in local elections,[144] seeking a national daily[145] or building up student and workers’ organizations.

During the Eucharistic Congress in Barcelona he issued a number of documents, including a manifesto to his followers and a letter to his son; in vague terms they referred to "assumption of royalty in succession of the last king", though also to pending "promulgation at the nearest opportunity"[150] and with no mention about the regency.

[151] The Carlist leaders were exhilarated and made sure that the Barcelona 1952 declaration, presented as end of the regency and commencing the rule of king Javier I, gets distributed across the party network; upon receiving the news, the rank and file got euphoric.

[153] The years of 1953–1954 provided a contrasting picture: the Carlist leaders boasted of having a new king,[154] while Don Javier withdrew to Lignières, reducing his political activity to receiving guests and to correspondence.

[158] His brief early 1955 visit to Spain en route to Portugal fuelled angry rumors of forthcoming rapprochement with the Alfonsists as Don Javier made some ambiguous comments,[159] named the 1952 statement "a grave error" and declared having been bullied into it.

In late 1955 Don Javier issued a manifesto which declared the Carlists "custodians of patrimony" rather than political party seeking power[162] and in private considered his royal claim a hindrance to alliance of all reasonable people.

[168] As prince Hugues was ignorant as to Carlism and he barely spoke Spanish, it seems that his father has never considered him own successor,[169] eager rather to free himself and the entire family from the increasingly heavy Carlist burden.

[172] According to another interpretation, Don Javier saw his son's involvement as an opportunity to consider new strategies for long-term gains, and changed course in the hope that the regime might one day crown the younger prince.

[177] He supported Valiente – his position gradually reinforced formally up to the new Jefe Delegado in 1958–1960[178] – in attempts to eradicate internal forces of rebellion against collaboration,[179] and to combat new openly secessionist groups.

First, in a symbolic gesture Don Javier declared Hugues "Duque de San Jaime", a historic title borne by Alfonso Carlos; then, he instructed his followers to envision the prince as the embodiment of "a king".

[192] Another group of scholars claim that the aging Don Javier, at that time in his late 70s, was increasingly detached from Spanish issues and substantially unaware of the political course sponsored by Carlos Hugo.

In 1967 he accepted the resignation of Valiente,[196] the last Traditionalist bulwark in the executive, and entrusted political leadership of the Comunión to a set of collegial bodies dominated by hugocarlistas; the move marked their final victory in the struggle to control the organization.

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.

[213] 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.

[231] In partisan discourse Don Javier is generally held in high esteem, though Left-wing Partido Carlista militants[232] and Right-wing Traditionalists offer strikingly different pictures of him.

Authors admitting their Hugocarlista pedigree claim that from his youth Don Javier has nurtured democratic, progressive ideas,[233] and in the 1960s he lent his full support to renovation of Carlist thought.

[234] Authors remaining within the Traditionalist orthodoxy suggest that although generally conservative, but in his 70s impaired by age, bewildered by Vaticanum II, misled and possibly incapacitated by his children, Don Javier presided over destruction of Carlism.

[240] Apart from minor pieces related to the Sixtus Affair, Chambord litigation and Halifax-Chevalier negotiations, he is discussed as a key protagonist in various works dealing with Carlism during the Francoist era.

[244] Two[245] point to his "contradictory personality" and admit that his stand "might seem confusing", though they claim that he was generally conservative[246] and was faithful to Traditionalist principles,[247] Don Javier was misguided and manipulated,[248] inadvertently legitimizing the change he did not genuinely support.