Answer
Gordian I was the great-grandfather of Gordian III. Gordian I, along with his son Gordian II, briefly ruled as co-emperors in 238 AD before being defeated and killed by Maximinus Thrax. Gordian III, born in 225 AD, became emperor in 238 AD at the age of 13. He was assassinated in 244 AD by Philip the Arab, who succeeded him as emperor.