15th Grenadiers of the Line (French) image - Heroes of The Napoleonic Wars II mod for Men of War: Assault Squad 2

A grenadier (from French, derived from the word grenade[1]) was originally a specialized soldier, first established as a distinct role in the mid-to-late 17th century, for the throwing of grenades and sometimes assault operations. At that time grenadiers were chosen from the strongest and largest soldiers. By the 18th century, dedicated grenade throwing of this sort was no longer relevant, but grenadiers were still chosen for being the most physically powerful soldiers and would lead assaults in the field of battle. Grenadiers would also often lead the storming of fortification breaches in siege warfare, although this role was more usually fulfilled by all-arm units of volunteers called forlorn hopes, and might also be fulfilled by sappers or pioneers.

Certain countries such as France (Grenadiers à Cheval de la Garde Impériale) and Argentina (Regiment of Mounted Grenadiers) established units of Horse Grenadiers and for a time the British Army had Horse Grenadier Guards. Like their infantry grenadier counterparts, these horse-mounted soldiers were chosen for their size and strength (heavy cavalry).