The letter "K" in the words "Knights" and "Knives" can be attributed to Viking Clan of K'Nigs that settled in Ireland. They built short swords, called K'Nives, because the Irish sourced iron was too weak for longswords. Later, the clan became a Mercenary Warband known as K'Nights. The K became silent in pronunciation over time as the Vikings eventually adopted the Anglo/Irish lifestyles.