Question: What happened to the British Isles and the continent Champagne-Ardenne and its neighbor is located in after the Roman Empire ended?

<P0-S0> The greater region maintained an industrial eminence into the 20th century, after coal replaced charcoal in metallurgy. <P0-S1> The trees and rivers of the Ardennes provided the charcoal industry assets that enabled the great industrial period of Wallonia in the 18th and 19th centuries, when it was arguably the second great industrial region of the world, after England. <SEP> <P1-S0> the byzantine empire, also referred to as the eastern roman empire, was the continuation of the roman empire in the east during late antiquity and the middle ages, when its capital city was constantinople (modern - day istanbul, which had been founded as byzantium). <P1-S1> it survived the fragmentation and fall of the western roman empire in the 5th century ad and continued to exist for an additional thousand years until it fell to the ottoman turks in 1453. during most of its existence, the empire was the most powerful economic, cultural, and military force in europe. <P1-S2> both ``byzantine empire ''and`` eastern roman empire'' are historiographical terms created after the end of the realm; its citizens continued to refer to their empire as the roman empire (greek: βασιλεία τῶν ῥωμαίων, tr. <P1-S3> basileia tôn rhōmaiōn; latin: imperium romanum), or romania (ῥωμανία), and to themselves as ``romans. '' <SEP> <P2-S0> the earliest known use of the phrase brytish iles in the english language is dated 1577 in a work by john dee. <P2-S1> today, this name is seen by some as carrying imperialist overtones although it is still commonly used. <P2-S2> other names used to describe the islands include the anglo-celtic isles, atlantic archipelago, british-irish isles, britain and ireland, uk and ireland, and british isles and ireland. <P2-S3> owing to political and national associations with the word british, the government of ireland does not use the term british isles and in documents drawn up jointly between the british and irish governments, the archipelago is referred to simply as "these islands". <P2-S4> nonetheless, british isles is still the most widely accepted term for the archipelago. <SEP> <P3-S0> Anglo-Saxons arrived as Roman power waned in the 5th century AD. <P3-S1> Initially, their arrival seems to have been at the invitation of the Britons as mercenaries to repulse incursions by the Hiberni and Picts. <P3-S2> In time, Anglo-Saxon demands on the British became so great that they came to culturally dominate the bulk of southern Great Britain, though recent genetic evidence suggests Britons still formed the bulk of the population. <P3-S3> This dominance creating what is now England and leaving culturally British enclaves only in the north of what is now England, in Cornwall and what is now known as Wales. <P3-S4> Ireland had been unaffected by the Romans except, significantly, having been Christianised, traditionally by the Romano-Briton, Saint Patrick. <P3-S5> As Europe, including Britain, descended into turmoil following the collapse of Roman civilisation, an era known as the Dark Ages, Ireland entered a golden age and responded with missions (first to Great Britain and then to the continent), the founding of monasteries and universities. <P3-S6> These were later joined by Anglo-Saxon missions of a similar nature. <SEP> <P4-S0> Science and technology in Wallonia, the southern region of Belgium (Europe), is well developed with the presence of several universities and research institutes.