In 823 there was an Arab expedition to Alava and Castille. In the description that is made of this expedition, mention is made to the assault on Alava by crossing a so-called "Gernika" valley. However, the description that is made of this valley does not coincide with the actual situation of Gernika. However, there was a Gernika in Alava, and that was, without doubt, the place through which the Arabs entered Alava