Jamb: Upright side of a door frame or window

Jambarts: Armour for the lower leg. See Greaves

Joggled: Construction held together using overlapping joints

Joinery: The smaller items of woodwork. Door, windows etc

Joist: A beam that supports a floor

Keep: Donjon; The defendable central part of a Norman castle. Either a Hall-keep with living quaters or a Shell-keep with open centre and walls with a sentry-walk

Kern: A lightly-armed foot soldier from Ireland or Scotland

Keystone: The voussoir at the top of the arch or vault

Knight: A medieval warrior belonging to a lord and providing military service to that lord

Knight-Bachelor: A lower ranked knight identified by the pennon worn the lance

Knight-Banneret: A higher ranked knight identified by the banner he flew

Knights Templar: Military and religious order founded in 1118 (More...)

Lady Chapel: Chapel dedicated to the Virgin at the East end of the church

Lance: A common weapon for both foot-soldiers and cavalry

Lancet window: Slender pointed window usually found in groups

Laver: The place where monks could wash within the cloister

lierne: Small ornamental sections of vaulting rib joining the main ribs

Lintel: Flat beam above a window or door

Longbow: A powerful bow up to six foot in height requiring great strength to draw

Loops: Small openings in a wall through which defenders can shoot arrows or other projectiles