Line Infantry refers to the soldiers forming the bulk of any dismounted force, as distinct from Guards, light infantry and more recently, special forces. Infantry of the Line are so called because they fought in rigid formations, unlike light troops, who fought in loose order. The seventeenth and eighteenth centuries saw expansion of the roles of the infantry, specialist grenadiers appeared and the role of skirmishers expanded. The Line Infantry was the remaining body of musket-armed foot soldiers. The tactical distinctions between infantry regiments disappeared in the nineteenth century, but remain in tradition. Most infantry units in the British Army are regarded as line infantry, including the regiments historically classed as light infantry. The exceptions to this are the Foot Guards, the regiments historically classed as 'rifles', the Royal Marines and the RAF Regiment and the special forces.
