…For there is no man there that bears a head, but that bears military arms; even boys of fourteen years of age are practiced with men in military discipline, every three weeks.
Wood, W., New-England’s Prospect, being a true, lively and experimental Description of that part of America commonly called New-England, London 1639
…you will have young men to muster the time that they must appear at muster must be so soon as they grow to any mans estate: this will be when they are about the age of 14, 15 or 16 years: Then not only more speedily, but also more perfectly all things are learned, the sooner the better. Fore Vergetius sayth truly, that it is better that a young men exercised should allege that his age to fight is not yet come, than he should truly lament that the same were already past. Let young men be exercised betimes, for it is readiness gotten by former practice that maketh a Soldier.
Cooke, E., The Character of Warre, or The Image of Martiall Discipline. London, 1626, Ch III