William the Conqueror, now known as William I of England, built the original part of the Tower of London fort and palace, known as the White Tower.
The Battle of Hastings began on October 14, 1066 between the opposing forces under Duke William of Normandy (later King William I of England) and King Harold Godwinson (also called Harold II) of England, the last crowned Anglo-Saxon King of England. King Harold Godwinson died on that first day of battle at Hastings.
After victory in the Battle of Hastings and the surrender of London, new King William I had his coronation at Westminster Abbey on December 24, 1066.
Early on, before the Norman aggressors set out for England, which was around Thursday 27th September, 1066 (arriving at Pevensey the next day), there is a full moon showing. The full moons for that time were only on Wednesday the 6th of September, and the next one after this was on Friday the sixth of October. For this reason, the day portrayed here has to be the sixth of September. The subsequent landmark Battle of Hastings took place on Senlac Hill in Sussex (South Saxons) on Saturday the fourteenth of October.