A French city must have saltpeter in its Strategic Resource box to build a musketeer.
Although often used to designate the flintlock-armed formations of a number of European countries, the term "Musketeer" generally refers to the King's Guard under Louis XIII and Louis XIV of France, immortalized in Dumas's famous novel. As such, the Musketeers served as a training ground for the young nobility, intended to be the elite of the army. Training not only included mastery of all weapons, from epee to musket, but instruction in social skills and military etiquette as well. In peacetime, the Musketeers served as the King's personal escort. Monsieur Treville, one of the Louis XIII's advisors and ardent sponsor of the Musketeers, and Cardinal Richelieu, who maintained his own company of guards, were political adversaries until the banishment of Treville following a 1642 plot to assassinate the Cardinal. Following that, the prestige of the Musketeers declined. In the military reforms that followed the death of Louis XIV, the Musketeers were disbanded and absorbed into the ranks of the French army.