Rise of Britannia Magna
Magnus Maximus (Latin: Flavius Magnus Maximus Augustus) (Born Hispania ca. 335 – August 28, 412), also known as Maximianus and Macsen Wledig in Welsh, was the de facto Roman Emperor of the Western Empire from 383 to 388,(True Emperor 386-388) and True Emperor of Britannia Magna from 383 to 412.
He was married to Elen (known in Welsh tradition as Elen Luyddog (Helen of the Hosts); also known as Saint Helen of Caernarfon) was a late 4th-century founder of churches in Wales who is remembered as a saint. She was thought to have been a daughter of the Romano-British ruler Octavius (half brother to Constantine the great).
As commander of Britainnia, he usurped the throne of the Western Empire from Emperor Gratian in 383 and killed him in battle in 386. However, through negotiation with Theodosius I, the Roman Emperor of the Eastern Empire the following year and after the return of the remainder of the Western Empire (Italy, Hispania, Pannonia, and Africa) to Theodosius's brother Valentinian II 388, he was made emperor in Britannia, and Gaul.
In 389 after the deal with Theodosius I and Valentinian II, Britannic Emperor Maximianus declared the Roman Provinces of Britannia and Gaul were to be renamed Britannia Magna (or Great Britain), this removed these provinces offically from the Western Roman Empire.
In the same year the Emperor announces that four new Britannic legions will be formed, two from each province of Britannia (Britannia Prima, Britannia Secunda, Maxima Caesariensis and Flavia Caesariensis) and Gaul (Gallia Cisalpina, Gallia Narbonensis, Gallia Aquitania, Gallia Belgica Prima, Gallia Belgica Secunda, Gallia Lugdunensis) to protect the coastline from raiding Saxons (in Britannia) and Franks and Vandals (in Gaul), their first action was to build several coastal protection forts around the coast of Britannia and northern coast of Gaul.
Due to the buildings of the forts and the four new legions Emperor Maximianus successfully stopped the raids by the Saxons, Vandals and Franks.
However in his later reign, in approx 407, the Franks, after taking the former Roman provinces of Germania Inferior and Germania Superior, did take a part of Gaul ( the provinces of Gallia Belgica Prima and Gallia Belgica Secunda), however the Franks did have to pay the Britannic Empire recompense for the provinces.
Death of Emperor Maximianus (383-412)
In 412 Emperor Maximianus dies in home in Londinium, he is succeded by his son Cystennin or Constantine (born 361) taking the Imperial name, the Britannic Emperor Constantine,
In 419 Emperor Constantine's youngest daughter Aurilia, married the 18 year old Western Roman Emperor Theodosius II (Flavius Theodosius Augustus) Their son Anthemius became Western Emperor in 450. In 421 Emperor Constintine delares his 25 year old son Flavius Maximus to be Augustus or his heir.
Death of Emperor Constantine (412-435)
In 429 Emperor Constantine dies after falling from his horse whilst riding in southern Britannia Secunda, he is succeded by his 33 year old son Flavius Maximus who takes the Imperial name Emperor Maximus.
Maximus has two sons, Octavian (born 422) and Arturious (born 431) from a young age it was clear that Arturious is the son who has the gift for ruling as his older brother Octavian appeared to be slow witted and had regular fits, in 432 Octavian dies in his sleep, it is unknown if he died naturally or was removed to make way for his younger brother. After Octavians death the Emperor Maximus names Arturoius Augustus.
Arturious marries Leontia, daughter of Eastern Roman Empire Leo I in 469, (he was 38 she was 12) although there was a large age difference and the marriage is almost purely political to start with in later years it appears that they grew to love each other, together they have five children, Magnus Flavius (473), Maria (474), Marcus Octavian (475) who became Augustus in 492, Lucius Julius (480), Marcian Hadrian(482)
Death of Emperor Arturious(435 - 495)
In 495 Emperor Arturious dies in his sleep in Eboracum in Britannia Secunda. He is succeded by his 20 year old elected son Marcus, who takes the name Emperor Octavian.