The combination of longbow and "long-knife" was probably picked up by Tolkien from descriptions of English archers of the Hundred Years War period. These describe many archers being armed with longbow, knife or dagger, lead mallet and buckler. This was only the poorer sort, the many mounted archers (mounted for swift movement not equestrian archery) would be better armed with either a falchion type of sword or, towards the end of the period , a hand and a half sword. These elite archers would be well equipped with a sallet, brigandine and perhaps some limb armour - sufficient to be useful in close combat.

To return to the "long-knife" this seems to have been in general what is called a "baselard" which had a relatively long and broad blade and a distinctive "H" shaped hilt, the term short-sword would not be inappropriate. In addition to the long-knife most would have worn an every-day dagger, the "ballock dagger" (it had two suggestive lobes where blade met hilt) which was used in eating as well as combat.