A regiment is a title used by some military units. The size of a regiment varies markedly, depending on the country and the arm of service.
Historically, in the seventeenth and eighteenth centuries, a full-strength regiment was typically supposed to be a thousand men, and was commanded by a colonel.
Today, there is no set size for a unit calling itself a "regiment", which may be:
The French term régiment entered military usage in Europe at the end of the 16th century, when armies evolved from collections of retinues who followed knights, to formally organised, permanent military forces. At that time, regiments usually were named after their commanding colonels, and disbanded at the end of the campaign or war; the colonel and his regiment might recruit from and serve several monarchs or countries. Later, it was customary to name the regiment by its precedence in the line of battle, and to recruit from specific places, called cantons. The oldest regiments which still exist include the 1521 Swedish Life Guards, the 1537 British Honourable Artillery Company and the French premier régiment d'infanterie de ligne, created from the ancient "bandes de Picardie" first established in 1479.