This chapter explores the contributions made by English veterans of the Dutch Revolt, amateur soldiers of the Honourable Artillery Company (HAC), and a handful of London printers to the evolution of the printed infantry drill manual in Jacobean England. Despite the years of peace that marked the reign of James I, thousands of English soldiers continued to travel to Europe to fight in the Low Countries, in the Cleves-Julich campaigns of 1610-14 and eventually, in 1618, in the Thirty Years’ War. On their return home these veterans voiced concerns about the poor state of military training and their fears that England could not withstand an invasion by Hapsburg Spain. Believing it vital that continental methods, notably Dutch innovations in infantry practice, be introduced into England, a number of veterans authored printed drill instructions for use by the trained bands, the military societies of London and contingents bound for Europe.1