Arfon means "opposite Anglesey" ('Ar' + 'Fôn' which is the soft mutation of 'Môn', the Welsh name for Anglesey). The name is ancient and has been used to designate the area since early medieval times. In the Middle Ages Cantref Arfon was an administrative unit of the Kingdom of Gwynedd. Arfon survived as a geocultural name (Welsh: bro) over the centuries and remains in use today. It is also sometimes found as a personal name (e.g. Arfon Griffiths).