Cos.  Hac tempestate prae valetudine Romanorum, vires funditus attenuatae Britanniae.  And Sigebert, conjoining this with the siege of Rome, saith:  Britannorum vires attenuatae, & substrahunt se a Romanorum dominatione.  And Zosimus lib. 6. The Transrhenane Barbarians_ invading all places, reduced the inhabitants of the island of Britain, and also certain Celtic nations to that pass, that they fell off from the Roman Empire; and being no longer obedient to the Roman laws_, [Greek:  kat’ heauton biateuein], they lived in separate bodies after their own pleasure.  The Britons_ therefore taking up arms, and hazarding themselves for their own safety, freed their cities from the imminent Barbarians.  In like manner all Brabant and some other Provinces of the Gauls imitating the Britons, freed themselves also, ejecting the Roman Presidents, and forming themselves into a sort of commonwealth according to their own pleasure.  This rebellion of Britain and the Celtic nations happened when Constantine usurped the kingdom_.  So also Procopius, lib. 1. Vandal. speaking of the same Constantine, saith:  Constantine being overcome in battle, was slain with his children: [Greek:  Bretannian men toi Romaioi anasosasthai ouketi echon; all’ ousa hypo tyrannous ap’ autou emene.] Yet the Romans_ could not recover Britain any more, but from that time it remained under Tyrants_.  And Beda, l. 1. c. 11. Fracta est Roma a Gothis anno 1164 suae conditionis; ex quo tempore Romani in Britannia regnare cessaverunt.  And Ethelwaldus:  A tempore Romae a Gothis expugnatae, cessavit imperium Romanorum a Britannia insula, & ab aliis; quas sub jugo servitutis tenebant, multis terris.  And Theodoret, serm. 9. de curand.  Graec. affect. about the year 424, reckons the Britons among the nations which were not then in subjection to the Roman Empire.  Thus Sigonius:  ad annum 411, Imperium Romanorum post excessum Constantini in Britannia nullum fuit.

Between the death of Constantine and the reign of Vortigern was an interregnum of about 14 years, in which the Britons had wars with the Picts and Scots, and twice obtained the assistance of a Roman Legion, who drove out the enemy, but told them positively at their departure that they would come no more.  Of Vortigern’s beginning to reign there is this record in an old Chronicle in Nennius, quoted by Camden and others:  Guortigernus tenuit imperium in Britannia, Theodosio & Valentiniano Coss. [viz.  A.C. 425.] _& in quarto anno regni sui Saxones ad Britanniam venerunt, Felice & Tauro Coss._ [viz.  A.C. 428.] This coming of the Saxons, Sigebert refers to the 4th year of Valentinian, which