Wales · Geographic county

Monmouthshire county flag

Sir Fynwy

Flag artwork supplied by the Flag Institute UK Flag Registry; reproduced as the registered public flag. Optimised to WebP without changing the design. Artwork and public-use information.

Registered county flag

County	Monmouthshire
Geographical grouping	Wales
Registration recorded by British County Flags	30 September 2011
Design attribution	Traditional
Status checked	24 October 2026

Design and symbolism

A blue-and-black divided field carries three gold fleurs-de-lys. The design is known as Inyr’s Banner or the Gwent Banner.

History and use

It derives from arms attributed by medieval heralds to King Inyr of Gwent and used by later local institutions. The modern realisation uses a bright blue to improve its contrast with black. HCI groups Monmouthshire with Wales; the flag’s story does not resolve the county’s historically ambiguous national status.

Sources and acknowledgements

County geography follows the Historic Counties Standard, published by the Historic Counties Trust, as used by RealCounties. Read our source and status guidance.

Flag-profile text: Historic Counties Institute, CC BY-SA 3.0, drawing on the credited research. Artwork has its own credit above.