Simplify the following text for a Grade 12 native English-speaking person.
Original: Upon Canute 's death ( November 12 , 1035 ) , Harold 's younger half-brother Harthacanute , the son of Canute and his queen , Emma of Normandy , was legitimate heir to the thrones of both the Danes and the English , but was unable to travel to his coronation , because his Danish kingdom was under threat of invasion by King Magnus I of Norway and King Anund Jacob of Sweden .
Simplified: Upon Cnut 's death ( 12 November 1035 ) , Harold 's younger half-brother Harthacnut , the son of Cnut and his queen Emma of Normandy , was legitimate heir to the thrones of both the Danes and the English . Harthacnut , however , was unable to travel to his coronation in England because his Danish kingdom was under threat of invasion by King Magnus I of Norway and King Anund Jacob of Sweden .