It is named after the River Morda, which, with the River Tanat, is one of the first major tributaries joining the River Severn as it wends its way from its birthplace on Plynlimon, mid-Wales, to the Bristol Channel.
The Irish doom metal group Mael Mórdha take their name from Máel Mórda mac Murchada and many of their songs are based on the events of the battle of Clontarf.