Maelgwn, who reigned in the first half of the 6th century, is one of the first historically verifiable rulers of Gwynedd. Known as ‘Maelgwn the Tall’, he was, it seems, a formidable warrior. He was also, if a contemporary account is to believed, a thoroughly bad man. A sermon by a 6th-century Welsh cleric called Gildas is our earliest source for Maelgwn’s life, and it is scathingly critical of him.
According to Gildas, Maelgwn came to the throne after killing his uncle. In remorse he briefly became a monk, but soon returned to the world of politics. He slew his wife and his nephew, so that he might marry the nephew’s widow. Gildas claimed that he revelled in the praise of his court poets, and neglected the Church. Gildas memorably dubbed Maelgwn ‘the dragon of the Isle’ – a reference to a beast of the Apocalypse and the king’s strong connections with Anglesey – and he condemned him as being the worst of five lamentable British rulers at the time.
In fact Maelgwn seems to have been, at times, a supporter of Christianity in its early years in Wales, and the patron of several early saints. He is also often linked with the foundation of Bangor by St Deiniol. His llys (court) was almost certainly on Anglesey, as Gildas suggests, but later sources also associate him with Deganwy on the mouth of the Conwy Estuary.
Maelgwn died in 547, according to some sources, from ‘the yellow plague’ (yellow fever).