It is associated in its origin with that development in warfare which made the mailed horseman, armed with lance and sword, the most important factor in battle. It was long believed that knight-service was developed out of the liability, under the English system, of every five hides of land to provide one soldier in war. It is now held that, on the contrary, it was a novel system in England when it was introduced after the Conquest by the Normans, who relied essentially on their mounted knights, while the English fought on foot. It existed in Normandy where a knight held a fief termed a "fief du haubert", from the hauberk or coat of mail (Latin: "lorica") worn by knights. Allusion is made to this in the coronation charter of Henry I (1100), which speaks of those holding by knight-service as "" (literally "soldiers who serve [or are subject to] their lands by means of armour").