Raymond received the surname Nonnatus — 'not born' — because he was extracted by Caesarean section from his mother's body after her death in labour, an extreme rarity in the early thirteenth century that almost no infant survived. He entered the new Order of Our Lady of Mercy for the Ransom of Captives (Mercedarians) founded by Peter Nolasco in 1218, and at twenty-five made his first ransom expedition to the Moorish Andalusian capitals.
On his second expedition to Algiers, when his funds ran out and he had not yet ransomed all the assigned captives, Raymond gave himself in their place as a hostage. He was held in chains for eight months. He continued preaching to fellow prisoners and to the Muslim authorities — for which he was condemned to be paraded through the streets and impaled on a stake. The sentence was commuted, but his lips were padlocked through the cheeks to silence him, and he was kept in this state until Peter Nolasco arrived with the ransom.
Pope Gregory IX created him a Cardinal in 1239 in recognition of his work. He set out for Rome but died of fever at Cardona, Catalonia, before reaching the city. He is venerated as the patron of pregnant women, of safe childbirth, and of all who are falsely accused or silenced — a triple patronage drawn directly from the episodes of his life.