Simplify the following text for a Grade 8 native English-speaking person.
Original: As one of the central figures of the Three Kingdoms period , he laid the foundations for what was to become the state of Cao Wei and was posthumously titled Emperor Wu of Wei .
Simplified: Cao Cao died in 220 , and his son Cao Pi followed him in control of the emperor . He eventually deposed him the same year and became Emperor Wen of Wei , making his father posthumously Emperor Meng of Wei .