When the nascent Imperium reunited with the [[Knight Worlds]] during the [[Great Crusade]], they found that, in addition to the [[Knights]] used in battle by the nobility, there were also lesser unarmed frames used by Drovers - the non-noble herdsmen who tended the fields and estates. One such popular and tested frame, the [[Drover Walker| "Drover suit"]], would be armed and adapted into the Sentinel widely used by the [[Imperial Army]] and [[Imperial Guard]]. {{Fn|23}}