The town took its name from count Rodrigo González Girón. It was he who, in the middle of the 12th century, banished the Moors from the region once and for all, and built the town on top of a former Roman castrum, itself once built on top of a Celtic settlement. The solid fortifications speak of the position on the frontier with Portugal. Paradoxically, although one of the most well defended European borders on both sides, this frontier is the most stable in all of European history and has remained virtually the same for 500 years. The only fighting to take place here was with Napoleon’s armies. Nowhere is the relation between square and margin more obvious than in such citadels.