"Across the battlefield, I saw the bodies of Jamuqa's(扎木和) men lying together like felled logs in the forest."

Following the defeat, Jamuqa fled into the mountains of Tannu(唐努). He hid throughout the winter of 1204. In the spring, he reappeared, escorted by two of his own generals who thought they knew where their best interests lay. They delivered Jamuqa to Temujin(铁木真).

"The generals expected a reward for betraying their leader and delivering him into the hands of his enemy. And I saw they got their reward."

felled: chopped down (about a tree)