An Arthurian Chronology according to Geoffrey of Monmouth

410/ End of Roman authority; appeal to Aldroenus; Constantine heads army; defeats Picts; made King

410-426/ Reign of Constantine. He marries and has three children: Constans (410), Ambrosius (425) and Uther (426)

428/ Constans murdered; Vortigern king; Ambrosius and Uther smuggled to Britain [Llydaw]. Arrival of Saxons [Gewis?].

428-440/ Build up of Saxons, including arrival of Reiwen who marries Vortigern. Visit of Germanus and Lupus.

440s/ Saxon wars. Vortimer deposes Vortigern and drives back Saxons.

449-455/ Vortimer killed; Vortigern restored; return of Hengist. Massacre of nobles. Vortigern flees.

455-457/ Ambrosius arrives; defeats and kills Vortigern. Made king. Defeats Hengist.

457-460/ Rebuilding programme. Late 460s/ Ambrosius killed; Uther quells north. Octa and Eossa imprisioned.

c470/ Birth of Arthur.485-494/ Uther poisoned; Arthur crowned. Octa and Eossa escape and are killed. Period of Arthur's battles.

495-506/ Arthur's peaceful reign and rise of chivalry.

506-515/ Arthur's Gallic campaign, culminating in imperial coronation.516-520/ Arthur's second Gallic campaign and march on Rome; Mordred's teachery; Arthur's return and fall at the battle of Camlann.

523/ Death of Arthur in Avalon.520-532/ Reigns of Constantine, Cynan and Vortipor.