|Book||The World of Ice & Fire (mentioned)|
In his old age, he turned his attentions westward and began to move against the Kingdom of Sarnor. As the Sarnori were contemptuous of the horselords, they sought to use the Dothraki in their own wars, offering them gold, slaves, and other gifts to fight their rivals. Khal Mengo took these gifts and then took the conquered lands as well, burning fields and towns and farms to return the grasslands to their former state, as Dothraki consider it sinful to cut the flesh of the earth with plows, spades, and axes. In time he was succeeded by his son Moro.
- The World of Ice & Fire, Beyond the Free Cities: The Grasslands.