The chevrons are an interpretation of the ancient arms of Iestyn ap Gwrgant, the last ruler of the Kingdom of Morgannwg. The de Clare family – Norman Lords of the Welsh Marches, under whose authority the ancient shire of Glamorgan was placed – used a similar design to Gwrgant's arms. Both sets of chevrons were once seen on the coat of arms of Mid Glamorgan County Council, in which the town of Pontypridd was situated prior to the Local Government Act of 1994.