Nightbringer | The Arthurian Online Encyclopedia


“Isle of Mona”
Welsh: Môn
Ynys Fon, Ynys Mon

A large island in the Irish sea of the northern coast of Wales, known as Môn to the Welsh.

A Welsh legend relates how Cei (Kay) went to the island to fight lions and engaged in combat with the fearsome Cath Palug.

The word mon means “separate,” “isolated,” which suggests that the island of Anglesey probably were called “Isle of Mona” because it was separated by sea from the counties of North Wales.

After the battle of Llanvaes, and Egbert was victorious over Merddyn, the English name was bestowed upon it. In 818 or 819 Mona was subdued by the Saxon king and called it Anglesey, or the Isle of the Angles, or English. In the twelfth century it assumed the title of Mon, mam Cymru, “Mona, the mother of Wales.”

Anglesey | 0 to 800 AD

Roman Period | 1st – 5th centuries AD
Anglesey, like much of Wales, was subject to Roman conquest and occupation during the first century AD. The Romans established a presence on the island, primarily for military and economic reasons. The island’s strategic location in the Irish Sea made it an important base for Roman campaigns in the region. Segontium (modern Caernarfon) on the mainland served as a Roman fort and administrative center for the region, including Anglesey. The Romans left their mark on Anglesey with roads, forts, and other infrastructure.

Early Christian Period | Late 4th – 7th centuries AD
With the decline of Roman rule in Britain in the early fifth century, Anglesey and other parts of Wales saw a period of transition. The spread of Christianity during this time began to influence the island, with Christian communities and religious centers emerging. Saint Seiriol, a Welsh saint, is associated with the founding of a religious community on the island, possibly on Penmon Priory.

Viking and Norse Incursions | 8th – 9th centures AD
Anglesey was not immune to Viking raids and incursions during the Viking Age. Viking raiders targeted coastal areas, including parts of Wales, in the late eighth and early ninth centuries. The raids by Norse and Danish Vikings led to significant disruptions and conflicts in the region. The island of Anglesey, with its accessible coastlines, would have been vulnerable to Viking attacks during this time.

Welsh Princes and Kingdoms | 7th – 9th centuries AD
Anglesey, like other parts of Wales, was divided into various smaller kingdoms or principalities during this period. Welsh rulers and princes held sway over different parts of the island, and the political landscape was characterized by both cooperation and conflict. The relationships between the Welsh rulers and external forces, such as the Anglo-Saxons and Vikings, played a role in shaping the island’s history.

Môn is the Welsh name for Anglesey. Isle of Mona and the Isle of Man derive their names from mon, which means “what is isolated,” “separate.”

See also
Branwen | The Legend of King Arthur
Inglecele | The Legend of King Arthur

Pa gur yv y porthaur | Poem 31 of the Black Book of Carmarthen, probably c. 1100