moribund strength

We are at the end of the battle at Roncesvalles; Roland feels himself dying and goes "toward Spain" to die as he's sworn to -- facing his enemy, and at the front of his army.

Holding Olivant in one hand and Durendart in the other, Roland went toward Spain and sat down under a tree that was some distance from the slain. He was so weak he could hardly walk. A heathen who was watching besmeared himself with blood and stealthily crept after the warrior. "He will die here between these four stones," thought the heathen. "I'll take Durendart and Olivant and say that we have triumphed and that I have slain Roland. All the Arab lands will rejoice forever." The marble blocks to which Roland had come were about a bowshot from his fallen companions.

The renowned warrior waited motionless until the heathen, thinking him dead, was close by. Then Roland raised the horn and with it struck the man on the helmet so hard that the lifeblood spurted forth from his eyes. "You'll get no thanks for daring to come near me!" he cried.