He used the strategy of feigning illness and placing an unknown at the time Lu Yi (Xun) in command, tricking Guan Yu into leaving the province unguarded. Then, Lu Meng attacked and captured the province, treating the civilians with care to turn them against Guan Yu. After Guan Yu was executed, Lu Meng fell to illness, and despite efforts from Sun Quan, died.
In the novel, however, he is possessed by the angered spirit of Guan Yu and is killed.
See also: Three Kingdoms