Paternal ancestors of Josep de Suelves i de Montagut came from two distinguished aristocratic Catalan families.
Representatives of the Montserrat line are recorded in the Middle Ages already; Francesc de Montserrat Vives made his name during the siege of Tarragona in the time of the Reapers' War (Guerra dels Segadors) in the mid-17th century and was awarded the marquesado of Tamarit by Carlos II in 1681.
In 1794 the title passed along the maternal line to Josep's great-grandfather, Joan Nepomucé de Suelves i Montserrat, an anti-liberal Tarragona deputy to Cortes of Cádiz.
 His son, 7th marqués de Tamarit, sided with the legitimist cause during the First Carlist War and was exiled afterwards.
His grandson, 8th marqués, Antoni de Suelves i d’Ustariz (Josep's paternal uncle), followed the family tradition forming part of Royal Council of the pretender Carlos VII and since late 1860s participated in preparations to another insurgency.
Antoni's younger brother, Joan de Suelves i d’Ustariz, married Buenaventura Montagut Félez, native of Tortosa and daughter of Josep Montagut Salvador, Conde Torre de l'Espanyol.
The couple had three children.

Josep, the oldest of the siblings, spent most of his childhood in family estates across Catalonia, to complete secondary education in colleges in Reus and Tortosa.
In the late 1860s he studied Derecho y Filosofia in Universidad Central of Madrid.
In 1885 he married María Goyeneche Puente (1862-1941), daughter of a Peruvian diplomat and Peruvian/Spanish conservative politician Juan Mariano Goyeneche y Gamio, 3rd Conde de Guaqui, by virtue of his family ties related to Navarre and Gipuzkoa.
When in 1886 despite his two marriages the 8th marqués de Tamarit died without issue, Josep inherited the marquesado.
He acquired also part of his uncle's wealth, consisting mostly of numerous landholdings around Tarragonese locations of Tamarit, Ferran and Morell, though also in some more distant municipalities.

Josep de Suelves i de Montagut  and María Goyeneche Puente had 3 children, Juan Nepomuceno Suelves Goyeneche, José Suelves Goyeneche and Carmen Suelves Goyeneche.
The oldest, Juan (b. 1887), in 1908 became the 10th marqués de Tamarit as his father renounced the title.
He joined the military and served in the cavalry Husares regiment, reaching the rank of a comandante during the Moroccan campaigns of the early 1920s.
At the outbreak of the Spanish Civil War in 1936 he joined the insurgents and assumed command of the Carlist Requeté battalion of Tercio de San Ignacio from Gipuzkoa; killed in action in June 1937 in Sopuerta in Biscay.
His granddaughter and great-granddaughter of Josep, herself a Peruvian citizen, married the oldest grandson of Franco in 1981.
Paternal ancestors of Josep de Suelves i de Montagut came from two distinguished aristocratic Catalan families. Representatives of the Montserrat line are recorded in the Middle Ages already; Francesc de Montserrat Vives made his name during the siege of Tarragona in the time of the Reapers' War (Guerra dels Segadors) in the mid-17th century and was awarded the marquesado of Tamarit by Carlos II in 1681. In 1794 the title passed along the maternal line to Josep's great-grandfather, Joan Nepomucé de Suelves i Montserrat, an anti-liberal Tarragona deputy to Cortes of Cádiz.  His son, 7th marqués de Tamarit, sided with the legitimist cause during the First Carlist War and was exiled afterwards. His grandson, 8th marqués, Antoni de Suelves i d’Ustariz (Josep's paternal uncle), followed the family tradition forming part of Royal Council of the pretender Carlos VII and since late 1860s participated in preparations to another insurgency. Antoni's younger brother, Joan de Suelves i d’Ustariz, married Buenaventura Montagut Félez, native of Tortosa and daughter of Josep Montagut Salvador, Conde Torre de l'Espanyol. The couple had three children.
Josep, the oldest of the siblings, spent most of his childhood in family estates across Catalonia, to complete secondary education in colleges in Reus and Tortosa. In the late 1860s he studied Derecho y Filosofia in Universidad Central of Madrid. In 1885 he married María Goyeneche Puente (1862-1941), daughter of a Peruvian diplomat and Peruvian/Spanish conservative politician Juan Mariano Goyeneche y Gamio, 3rd Conde de Guaqui, by virtue of his family ties related to Navarre and Gipuzkoa. When in 1886 despite his two marriages the 8th marqués de Tamarit died without issue, Josep inherited the marquesado. He acquired also part of his uncle's wealth, consisting mostly of numerous landholdings around Tarragonese locations of Tamarit, Ferran and Morell, though also in some more distant municipalities.
Josep de Suelves i de Montagut  and María Goyeneche Puente had 3 children, Juan Nepomuceno Suelves Goyeneche, José Suelves Goyeneche and Carmen Suelves Goyeneche. The oldest, Juan (b. 1887), in 1908 became the 10th marqués de Tamarit as his father renounced the title. He joined the military and served in the cavalry Husares regiment, reaching the rank of a comandante during the Moroccan campaigns of the early 1920s. At the outbreak of the Spanish Civil War in 1936 he joined the insurgents and assumed command of the Carlist Requeté battalion of Tercio de San Ignacio from Gipuzkoa; killed in action in June 1937 in Sopuerta in Biscay. His granddaughter and great-granddaughter of Josep, herself a Peruvian citizen, married the oldest grandson of Franco in 1981.
Josep de Suelves i de Montagut