After finishing a course in paleography and diplomatics in the Faculty of Philosophy and Arts of the University of Barcelona, de Fluvià became involved in genealogy and heraldry.

In 1984, de Fluvià received the Arenberg Prize in genealogy (1984) and since 1985, he was a member of the Académie Internationale d'Héraldique (International Academy of Heraldry).

He was founder and president (1983–2007) of the Societat Catalana de Genealogia, Heràldica, Sigil·lografia, Vexil·lologia i Nobiliària (Catalan Society of Genalogy, Heraldry, Sigillography, Vexillology, and Nobility).

On 24 October 2007, he founded the Institució Catalana de Genealogia i Heràldica (Catalan Institution of Genealogy and Heraldry) (ICGenHer) being the chairperson until he died in 2024.

[2] In 1953, de Fluvià was a member of the monarchical group Joventut Espanyola d'Acció (Spanish Youth of Action) (JEA).