These included a '' ( Lesser George '' insignia ( thought to have been worn by Charles I at his execution , and now at Windsor Castle ) and a St Andrew 's Cross ( now at Edinburgh Castle ) , which is an insignia of the order of the Thistle , and also a ruby ring . These included a `` Lesser George '' ( thought to have been worn by Charles I at his execution , and now at Windsor Castle ) and a St Andrew 's Cross ( now at Edinburgh Castle ) ) , which are insignia of the orders of the Garter and the Thistle , and also a ruby ring .