Complex sentence: Harold organized an army and defeated Harald Hardrada's forces in the northern parts of England just months before the Battle of Hastings on October 14,1066, where he was slaughtered in battle by William the Conquerer's forces during the successful Norman conquest of England.
Split into simpler sentences: Harold organized an army and defeated Harald Hardrada's forces in the northern parts of England just months before the Battle of Hastings on October 14,1066. There, he was slaughtered in battle by William the Conquerer's forces during the successful Norman conquest of England.