International audienceFrom Tenth to Thirteenth century, the relations between Christians and Muslims around the Mediterranean Sea multiplied, competition was on the increase and confrontations became more and more regular and violent. This growing militarization of the contact included the beginnings of professionalisation and, on the Christian side, formalisation and institutionalisation. The capture of the enemy and the system of ransom were included in this process: at the beginning of the 13th century, the first specialised instances of redemption appeared in the Iberian Peninsula (Trinitarian and Mercederian). These did not appear like a bolt from the blue: it had been in the Iberian background, in the dividing line between Christendom...