The Mabinogion
The Mabinogion tale The Dream of Rhonabwy is set during Madog's reign. The central character, Rhonabwy, is one of Madog's retainers sent to bring in Madog's rebellious brother Iowerth Goch ap Maredudd. His titular dream contrasts his own time with the grandeur of King Arthur's period.
Read more about this topic: Madog Ap Maredudd