Raymond was born around 1110 in Saint-Gaudens in Comminges (the Pyrenean French-Spanish frontier region of southwestern France) to a Gascon Catholic family. He became a Cistercian monk at the Abbey of Scala Dei at Pradier in French Languedoc.
Around 1140, crossing into Spanish Navarre with a party of Cistercian monks, Raymond founded the Abbey of Fitero in Navarre — the first Cistercian foundation in Spain (pre-dating the more famous Cistercian foundations of Poblet, Santes Creus, and Las Huelgas).
In late 1157, the Templar Knights surrendered the fortress of Calatrava in southern Castile (on the frontier of the reconquered Catholic territory and the Almohad Muslim territory) — declaring that they could not defend the fortress against the Almohad Muslim advance.
King Sancho III of Castile offered the fortress to any Catholic order that would undertake to defend it. Raymond of Fitero — together with his fellow Cistercian Diego Velázquez (a former knight of King Alfonso VII of Castile) — accepted the defence-commission and founded the Order of Calatrava in January 1158.
The Order of Calatrava — the principal Spanish-Catholic military-religious order — combined the Cistercian monastic discipline with the military-knightly apostolate of defending the Spanish Reconquista frontier against the Almohad Muslim military advance. Raymond governed the Order from its foundation in January 1158 until his death in January 1163.
The Order was institutionally affiliated to the Cistercian Order (affiliated as a filial of the Cistercian Abbey of Morimond) and followed the 'Definitions of Calatrava' that combined the Cistercian monastic-liturgical discipline with the distinctive military-knightly apostolate.
Under Raymond's governance and that of his immediate successors, the Order of Calatrava became the principal Catholic-military instrument of the Reconquista in southern Castile and subsequently in Andalusia — producing the affiliated Iberian military-religious orders of Alcántara (1166), Santiago (1170), Avis (1162, Portugal), Montesa (1317), and Christ (1319, Portugal-successor of the suppressed Templars).
Raymond died at Ciruelos in Toledo on January 15, 1163.

