The main battle sequence had a detailed script treatment of over 20 pages and a maximum of 8 cameras rolling simultaneously.
The main character's name was supposed to be that of an actual historical figure called Ma Xinyi, but was changed to Pang Qingyun in order not to reflect badly on the estate of Ma's descendants, who believe that their ancestor was a good man.
Up to 500 stunt horses were used.
The film was originally titled "The Blood Brothers". Director Peter Chan said it was influenced by the late Chang Cheh's 1973 film "The Blood Brothers", which is itself based on a famous high profile assassination of a local governor in 1870, but denied that it is a remake. He also decided to change the title to The Warlords in order to avoid confusion.