out. the tower of london dates back some one thousand years. the crown jewels are kept here. and the tower is also home to a flock of captive ravens. they are looked after by the yeoman warder raven master. riley to be here where the remains are so the ravens are out and about the moment we let them out chris casey is a retired staff sergeant his current position is the crowning glory of his career after twenty two years in the british army. to most people the ravens all look the same but not to their way the master. so that one over there that you see them one stone through the of is harris is