This is a banner of the arms attributed to Owain Gwynedd whose kingdom covered most of the present day county. This same pattern of three gold eagles on a green field, arranged horizontally, was mentioned by the seventeenth century poet and historian Michael Drayton as the banner borne by the men of Caernarfonshire at Agincourt. “Those of Caernarvon…Three Golden Eagles in their ensign bought,” The county’s long association with the three eagles was maintained in the design of the arms borne by the later county council where they appeared as a horizontal band across the middle of the shield. The eagles of Snowdonia were used on the arms of the Caernarfonshire County Council (1889-1974) and on the badge of the Caernarfonshire police in the 1940’s. The flag continues the age old association.
For further information about the registration and the adoption of the flag see: