Brigade is a term from military science which refers to a group of several battalions (typically two to four), and directly attached supporting units (normally including at least an artillery battery and additional logistic support). A brigade is smaller than a division and roughly equal to or a little larger than a regiment. Strength typically ranges between 1,500 and 3,500 personnel.
A brigade is usually commanded by a brigadier general or a colonel. In colonial powers such as the British Empire, brigades frequently garrisoned isolated colonial posts, and their commanders had substantial discretion and local authority.
The term derives from Italian "brigata" or Old French "brigare," for company, which in turn derives from a Celtic root "briga," which means strife.