Origin
War-Yore was created by Doug Moench and Jim Craig in 1977 and first appeared in Master of Kung Fu #5.
Character Evolution
Eric Slaughter’s shattered psyche used personas of multiple historical figures and costumed vigilantes as aliases: Robin Hood, Attila, Saint George, Viking Hrolf Kraki, Shira-Kawa’s Savior, Red Baron, Black Ninja, and Slayer in Darkness. In a more lucid moment he combined all his personalities and used his MI6 codename War-Yore.