Excerpts from Books and Wikipedia
"William claimed to have been promised the throne of England by King Edward the Confessor, but Harold, although he had sworn an oath to support William, had been crowned instead on Edward's death in January 1066." William introduced Norman law and feudalism to England, and French became the language of his court. [Furtado: 1001 Days] The Battle of Hastings was the end of Anglo-Saxon rule in England. Construction on the Tower of London began in 1077. [Wikipedia: Timeline of Middle Ages]