А3. Specify the name of the ruler, who described in the passage from the source of IX century: «At a time when there was a stubborn and almost uninterrupted struggle against the Saxons, <...> deploying garrisons in the proper border areas, went to Spain with as much power as possible. He crossed the Pyrenees mountains, all the cities and fortresses on his way surrendered, and he was already returning with a sound army; and only in the Pyrenees themselves, on the return journey, he had to experience the Basque treachery somewhat. Namely, when the army was walking along the extended line, as far as the gorge of the valley permitted, the Basques, setting up an ambush on top of the mountain ... having attacked from above, shot down the rear guard ... In this battle with many others, Eggigard, the head of the table, Anselm, the palatine, and Roland , head of the Breton boundary. And this act has not been able to be avenged until now, for the enemy, upon the accomplishment of this, was so scattered that it was impossible even to know where to look for it...».