Together with the Celts and Britons, the Franks are one of the civilizations belonging to the Western European culture. Their major advantage is their strong cavalry. The Franks are able to build castles at a 25% discount. It allows them to build the strong unique units and siege weapons, and advance to Imperial Age, faster than other civilizations. All of their cavalary units have 20% more hitpoints; this is their best advantage when the game proceeds to a later stage. Their Paladins (the strongest cavalary units) in Imperial Stage is extraordinarily strong. Interestingly, their unique unit is the Throwing Axeman, a short-range throwing axe attack unit.
Unlike most other civilizations, the Franks' Throwing Axeman are not capable of being a major force for the civilization themselves as an offensive unit, however they are very effective when accompanying defense of castles and towers. This is especially noteworthy if you're using Castles offensively (placing them directly outside the enemies base.) However like most units that consume gold, it's not suggested that you rely on Throwing Axemen solely if you expect a lot of casualties. Also they are useful when accompanied with the cavalary units.