MEDIEVAL WARFARE

Castles and Artillery 

Castra
Castellum (literally "little castra")
Roman  villa
Masons
Moat (fosse)
Palisade (medieval word for stockade)
Drawbridge
Motte and bailey castle
Baliff
Crusading Movement
Fire
Donjon (keep):  source of our word “dungeon”
From wood to stone; and from square to round forms
Catapult and Trebuchet
Ballista
Crenelation
Machicolation
Hoardings
Concentric Fortifications
Portcullis
Chateau Gaillard
Richard the Lionheart
Krak des Chevaliers
Chateau de Coucy
Castle de Coucy
Erich von Ludendorff