The battle of Atapuerca Historical milestone · Atapuerca, Burgos (Alfoz), Burgos Image of Atapuerca, not of the place itself. Ferdinand I of León and his brother García Sánchez III of Pamplona, both sons of Sancho III the Great, clashed on the plain facing the Atapuerca mountains on 1 September 1054. The conflict stemmed from the unequal inheritance divided by their father in 1035, which had left García the bulk of the former county of Castile and Ferdinand a diminished domain, and it came to a head when, according to the chronicles, Ferdinand imprisoned his brother after a reconciliation visit at Nájera, and García, upon escaping, declared war on him with the support of their other brother, Ramiro I of Aragon. The king of Pamplona died of wounds suffered in the battle, and his son was proclaimed king on the battlefield itself, after paying homage to the victor. 1 de septiembre de 1054 Photo: Mario Modesto Mata (CC BY-SA 3.0) What to see and do in Atapuerca