Simplify the following text for a Grade 5 native English-speaking person.
Original: According to Kojiki and Nihonshoki , he was the fourth son of Emperor Nintoku and his consort Iwanohime , and therefore a younger brother of his predecessor Emperor Hanzei . He sat on the throne after Hanzei died and ruled for 41 years .
Simplified: He was the younger brother of Emperor Hanzei .