A regiment is a military unit. Its role and size varies markedly, depending on the country, service, or specialisation.
In Medieval Europe, the term "regiment" denoted any large body of front-line soldiers,[1] recruited or conscripted in one geographical area, by a leader who was often also the feudal lord in capite of the soldiers. Lesser barons of knightly rank could be expected to muster or hire a company or battalion from their manorial estate.
By the end of the 17th century, infantry regiments in most European armies were permanent units, with approximately 800 men and commanded by a colonel.