The term “Trained Band” was indicative to England (and later early Colonial America). Their origins were born of The English Civil Wars of the 17th Century and Oliver Cromwell's “New Model” Army. The “Trained Bands” would also bear linage to The Militia System. Trained Bands (which first originated in London, England). Were composed of Men (aged 16 to 50). They were trained (on a rather inconsistent schedule), in various Military tactics as well as weapons – with this mostly regulated to The Matchlock.
Unlike a traditional “Militia System”, The Trained Band Recruits did not fight as a single Unit. The “best trained” and most “capable” of Men were gathered and formed into separate Units (when needed). Most of The Trained Band System was abolished in the 18th Century in England. The practice however carried on into early Colonial America (17th Century). Many “Trained Band” Colonists were formed for self-defense (as early Colonists were not supported by England's Military in theory). These Men (some of which may have been in Bands in England) – would form the basis for The American Militia System.