Wikimedia They weren’t always enemies. Before William of Normandy and Harold Godwinson were deadly adversaries on the battlefield at Hastings in 1066, vying for the throne of England, they were comrades and brothers in arms. It’s a tragic journey from unlikely allies to mortal enemies. And it’s one of the lesser-known stories in the Bayeux tapestry, which opens for viewing at the British Museum in London this September. As a medieval historian, …