In November 1143, Ramon Berenguer IV, Count of Barcelona, and the Order of the knights Templar signed an agreement to solve the dispute caused by the will of the Aragonese king Alfonso the Battler. In one of his arrangements, the Count promised the Order the fifth of future conquests. Historians have considered it as the fifth part of the lands. This article suggests a different interpretation: the fifth is not related to any territory distribution but to a revenues one which would be collected in all the al-Andalus regions to be conquered by the Count and the Templars from then on. This seems to have taken place in Tortosa and Lleida where the Order started very quickly to acquire important domain, although no documents about land grants w...