Upon his return to Spain he co-founded[9] Fomento de la Prensa Tradicionalista, the company which re-launched El Correo Catalán; he was also one of major landholders in the Roquetes-Nou Barris area.

Already in 1922 he signed a manifesto declaring Alfonso XIII a prospective legitimate Traditionalist heir as the direct Carlist dynasty was already certain to extinguish;[25] when entering the Barcelona Diputación Provincial[26] he was representing Lliga Regionalista of Francesc Cambó.

[29] Other sources suggest he joined efforts to build a "partido católico duro", promoted by the local ecclesiastical authorities as a Catholic alliance holding together different breeds of ultraconservative, conservative and right-wing groupings.

Already in June 1931 he co-founded Reacción, a weekly which pledged to confront Liberal and atheist "acción demagógica, disolvente y corrosiva" by supporting traditional values.

[35] In June he contributed to opening of Circulo Central Tradicionalista in Barcelona and became its vice-president,[36] later growing to full presidency;[37] following a related Carlist manifestation he was briefly detained by the authorities.

[38] It remains a bit of a paradox that within the Catalan Carlism Sivatte, himself an ex-Liguero, formed part of the faction which advocated bold stand and doctrinal intransigence, as opposed to the group of older leaders used to behind-the-scene dealings.

[54] Working closely with UME on military dispositions of Catalan requetés, Sivatte was deeply involved in preparing detailed Carlist plans for rebellion both in Barcelona and in Catalonia.

When the news of final deal with the military having been concluded arrived from Pamplona, on July 18 Sivatte and Caylá met to issue local insurgency orders, effective for the next day.

[65] He was also engaged in Frentes y Hospitales, the Carlist-led organisation called to treat the wounded and assist those serving on the frontline, though there are somewhat conflicting accounts of his exact role.

As one of them, Comisión para Asuntos, constantly attacked by the FET Catalan branch,[69] was renamed to Jefatura Regional de la Comunión[70] at unspecified time in 1938.

Within Carlism he formed the intransigent faction, headed by Manuel Fal Conde,[77] and pursued the strategy of preserving Traditionalist identity by refusal to join any Francoist structures.

In 1940, during the first anniversary of Nationalist conquest of Barcelona, Sivatte was detained in the Modelo prison;[79] in 1942, during the Carlist Mártires de la Tradición feast, he was joined by commander of the IV Región Militar, general Alfredo Kindelán.

Increasingly perplexed by contacts with the Alfonsinos and fearing some sort of dynastic compromise, as means of protest in 1944 Sivatte resigned from Junta Nacional Carlista, though he retained his post of the Catalan jefe.

[92] Ley de Sucesión, supported by Fal in the referendum,[93] made Sivatte believe that Franco opened the way for a distant Alfonsist restoration and pushed him for increasingly ultimative tone.

[94] The 1948 Aplec de Montserrat, intended as most bold demonstration of Carlist intransigence so far, was banned by the authorities with no protest recorded from national Traditionalist leaders.

[95] When Catalan Carlists issued another letter,[96] in February 1949 Fal attempted a last minute rescue mission and travelled to Barcelona, only to be informed that "por aquel camino el carlismo no podía caminar".

[103] The latter did not assume a formal shape and remained a loose group; their organizational emanation was Centro Familiar Montserrat, functioning as a social circulo rather than as a political body.

[104] Politically Sivatte maintained his previous stand: recognition of Don Javier as legitimate leader combined with opposition to regency formula, to dynastic compromise and to appeasement versus Francoism.

[109] This so-called Acta de Barcelona was immediately followed by a number of statements which seemed to play down the declaration,[110] vacillation which started to erode Sivatte's recognition of Don Javier.

[111] When efforts to construct a mausoleum of fallen requetés in Montserrat reached a breakthrough in 1952, Sivatte opposed the project since it was formatted as part of the Francoist propaganda exercise.

[114] On the other hand, the deposition of Fal seemed to ease the relationship with Javieristas,[115] especially that in 1956 Don Javier made conciliatory gestures towards Sivatte[116] and that year the two groups agreed to stage common Montserrat feast.

[120] Sivatte, fearing another reverse step, refused; moreover, he presented the declaration at Junta Suprema de las Regiones, a freshly formed and somewhat rebellious Carlist body bent on preventing a pro-Juanista and pro-Francoist turn.

[129] When in late 1957 a large group of Traditionalists leaning towards dynastic accord with the Alfonsinos declared Don Juan the legitimate heir, Sivatte felt genuine Carlism should be immediately given new momentum.

[133] The declaration pledged to safeguard Carlist spirit against mounting distortions, principally against falsifications enforced by Francoism, the system which "ha faltado esencialmente" and which was in fact not opposed but rather supported by Don Javier, who played a double game.

[141] In the early 1960s it became evident that RENACE instead of a dynamic renovating force turned out to be just another Carlist splinter faction, though its doctrinal purity and intransigence versus Francoism[142] made it a point of reference within the Traditionalist realm.

[152] Gradually the group started to emphasize its ultraconservative Catholicism,[153] calibrated against the spirit of Second Vatican Council and its timid Spanish incarnations, especially the so-called Law on Religious Liberties.

[155] As late as 1964 Sivatte tried to maintain correct relations with Don Carlos Hugo,[156] but the attempt backfired as significant number of Sivattistas, including Carles Feliu de Travy, left RENACE and re-integrated within Javierismo.

In 1970 it seemed reinvigorated when representatives of Juntas de Defensa and envoys of RENACE met in Estella to co-ordinate their activities; the meeting produced nothing but a few documents,[161] eclipsed by what looked like impressive dynamics of the socialist-controlled Partido Carlista.