Christine de Pizan, a French noblewoman, is notable not only for her poetry, but for having written this book on the virtues of martial training. The work is largely based on Vegetius’s De Re Militari, but Christine adds in plenty of commentary unique to the military situation of 15th century France.
Most interesting is her section on archery, as the book was coincidentally written just a few years before the disaster at Azincourt.
Vegetius says that as carrying a sling is very light, it is a very useful thing. It sometimes happens that a battle takes place on stony ground, or that it is necessary to defend a mountain. Even in the assault or defense of a fortress a sling can be very useful. It was formerly held in such high esteem that in some of the Greek islands mothers would not give food to their children until they had struck their meat with a slingshot blow. Along with this they taught them how to shoot with a bow or crossbow. Their teachers instructed them to hold the bow on their right side with the left hand, and then the cord was drawn by the right hand with great force and skill, the arrow near the ear, the heart and eye fixed steadily on the mark and attentively aimed. In this art young Englishmen are still instructed from early youth, and for this reason they commonly surpass other archers. They can hit a barge aimed at from a distance of six hundred feet. Vegetius says that this art must be practiced constantly even by skilled masters, for practice is necessary. Cato says in his book of arms that good archers are very useful in battle. Claudius testifies to this when he says that archers and those trained in throwing darts overcame their enemies with relatively few men; so does the valiant fighter Scipio the African.
It is rare to find a contemporary source which gives quantitative information on just how accurate archers were, or were expected to be. It is not clear if Christine had ever seen an English archer first-hand, or was repeating received knowledge. Nonetheless, it seems reasonable that an experienced archer would be able to consistently hit a “barge” from 200 yards. How big was a medieval barge? Certainly bigger than a man, probably smaller than a formed battalia.
This is practice-range accuracy, however. On the actual battlefield we could expect accuracy to drop precipitously. In the age of musketry, the percentage of bullets which could be expected to hit, both on the practice range and on the battlefield, are well documented. There is scarce information for either on arrows.