After the death of the King of England, Edward the Confessor , and breaking the agreement that he had signed with the Duke of Normandy, William , Harold was made king . In 1066, claiming a legitimate claim to the island, William invaded England. On October 14 the Saxon and Norman forces met at Hastings; the battle lasted all day, until Harold was killed by an arrow that pierced his eye. The Duke of Normandy was nicknamed William the Conqueror and was crowned William I of England . The dynasty of the Saxons ended and that of the Normans began.
At his coronation, William pledged to abide by the existing laws and customs in England. His reign was characterized by order and peace, but achieved through violence and cruelty that made him very unpopular among his subjects. During a battle in Rouen (France) his horse, possibly frightened by the fire, stopped short and Guillermo hit violently against the pommel of the saddle. You have to remember that Guillermo was extremely obese... one of those who don't see it when they pee. That accident caused the perforation of the intestine with the consequent filtration of the intestinal content into the abdominal cavity, causing peritonitis. After several days of terrible pain, on September 9, 1087 he died.
When the body arrived at Saint Stephen of Caen, where it was to be buried, it was a ticking time bomb:pus, intestinal content, gases from decomposition... and, to top it off, it had swollen so much that it did not fit in the sarcophagus of stone. They couldn't think of anything else but to push the body and put it under pressure... the body exploded and spilled all its contents . Retching, vomiting, foul odor...
Sources:BBC, History Learning site, Royal History