Rough Riders are specialised mounted cavalry units found among numerous Astra Militarum regiments from Feral and Frontier Worlds where riding animal mounts remains a commonplace military skill. Many primitive cultures from such worlds retain the use of such mounted units in warfare. The Imperial Guard often employs these mounted cavalry units on the field of battle, where they are especially suitable for uneven terrain that is unsuitable for tracked vehicles. They also act as scouts, patrols, and fast response troops, able to operate on their own for extended periods of time deep behind enemy lines.
From games at various shows and Simon’s collection.