Iñigo (Spanish-Basque variant of Ennecus / Latin Innicus) was born around 1000 in Calatayud, Aragon — the principal medieval Aragonese town on the Jalón river — to a Spanish noble family of the reconquest-era Catholic Aragonese-Castilian tradition.
Entering the Benedictine monastery of San Juan de la Peña in the Pyrenees (the principal medieval Aragonese royal monastic centre, the pantheon of the Aragonese kings and the original resting place of the Holy Grail per the Aragonese tradition), Iñigo became a monk and was chosen for hermit life on the mountains around the monastery.
Around 1029, King Sancho III the Great of Navarre and Aragon — undertaking the Cluniac reform of the Castilian monasteries — appointed Iñigo as abbot of the Abbey of San Salvador de Oña in Castile, the principal medieval Castilian monastic centre and the royal pantheon of the Castilian rulers.
For 28 years (1029–1057) Iñigo governed Oña — introducing the strict Cluniac monastic discipline in place of the previous mixed canonical-monastic observance, producing the characteristic Castilian-Cluniac monastic culture of the 11th century. The Oña reform extended through the Cluniac affiliated houses across the Castilian and Leonese kingdoms, producing the Spanish-Cluniac monastic-reform tradition that would produce St. Dominic of Silos and the Spanish-Catholic-reconquest religious-cultural transformation.
He died at Oña on June 1, 1057. The distinctive Spanish-Basque royal Christian name 'Iñigo' — derived from devotion to this 11th-century Catholic saint — produced the royal Christian name borne by countless medieval and early-modern Iberian rulers, most including the baptismal name of St. Ignatius Loyola (Íñigo López de Loyola, 1491–1556, the founder of the Society of Jesus) — making Iñigo of Oña the direct namesake-saint of the St. Ignatius and the entire Jesuit Catholic tradition.

