It is likely that the White Castle was first settled by the ancestors of the Votadini tribe, whose main eastern capital was Dunpender, due north. The fort is ideally placed to strategically control the northern end of one of the main passes through the Lammermuirs, along the Whiteadder Water. With the further fortifications three miles further east at Blackcastle and Greencastle it would have been ideally placed for a beacon to alert the tribe in case of an invasion from the south.