Maximus (-a, -um).

Emperor Magnus Maximus, known as Macsen Wledig

Maximus married Elen / Helen, a Breton princess of Seguntium / Caernarvon. She was the only one Roman Impress from the Breton's stock. He got from her Victor.

Flavius Magnus Maximus was the commander of the legions in Britannia. In 383 he usurped the throne against co-emperor Gratian (

who ruled in the west)

. Gratian’s co-emperor Theodosius I (whoruledin the east) made him emperor of Britain and Gaul (Gratian retained Italy, Africa, Spain and Pannonia).In 387 Magnus Maxumus tried to invade Italy, but was defeated by Theodosius I. He died the next year. Magnus Maximus is also called Macsen Wledig in Welsh. According to a Welsh legend, he married the Welsh princess Elen. Although the story is most likely fictional, there is evidence for some of its claims. Mascen is often referred to in Welsh poetry as a comparison to later Welsh leaders.