The knight sword is the single handed cruciform sword of the High Middle Ages, in common use between ca. 1000 and 1350, possibly remaining in rare use into the 16th century. Knight swords correspond to Oakeshott types XI, XII and XIII. They are generally considered to be descendant from the swords of the migration period and Vikings, generally referred to as spatha from the Latin. A combination of the Oakeshott and Peterson Typologies shows a chronological progression from the Viking sword to a "transitional sword", type X, which incorporated elements of both Viking and arming swords. This "transitional sword" continued to evolve into to the presently defined arming sword.