Question: when did the foreign group that conquered the country where the experiment took place around AD 43 began to fall?

full_context: Document 1: British Isles: Hiberni (Ireland), Pictish (northern Britain) and Britons (southern Britain) tribes, all speaking Insular Celtic, inhabited the islands at the beginning of the 1st millennium AD. Much of Brittonic-controlled Britain was conquered by the Roman Empire from AD 43. The first Anglo-Saxons arrived as Roman power waned in the 5th century and eventually dominated the bulk of what is now England. Viking invasions began in the 9th century, followed by more permanent settlements and political change—particularly in England. The subsequent Norman conquest of England in 1066 and the later Angevin partial conquest of Ireland from 1169 led to the imposition of a new Norman ruling elite across much of Britain and parts of Ireland. By the Late Middle Ages, Great Britain was separated into the Kingdoms of England and Scotland, while control in Ireland fluxed between Gaelic kingdoms, Hiberno-Norman lords and the English-dominated Lordship of Ireland, soon restricted only to The Pale. The 1603 Union of the Crowns, Acts of Union 1707 and Acts of Union 1800 attempted to consolidate Britain and Ireland into a single political unit, the United Kingdom of Great Britain and Ireland, with the Isle of Man and the Channel Islands remaining as Crown Dependencies. The expansion of the British Empire and migrations following the Irish Famine and Highland Clearances resulted in the distribution of the islands' population and culture throughout the world and a rapid de-population of Ireland in the second half of the 19th century. Most of Ireland seceded from the United Kingdom after the Irish War of Independence and the subsequent Anglo-Irish Treaty (1919–1922), with six counties remaining in the UK as Northern Ireland.
Document 2: East–West Schism: In 476, when the last emperor of the western part of the Roman Empire was deposed and the western imperial insignia were sent to Constantinople, there was once again a single Roman Emperor. However, he had little power in the West, which was ruled almost entirely by various Germanic tribes. In the opinion of Randall R. Cloud, the permanent separation of the Greek East from the Latin West was ``the fundamental reason for the estrangement that soon followed between the Greek and the Latin Christians ''.
Document 3: Fall of the Western Roman Empire: Relevant dates include 117 CE, when the Empire was at its greatest territorial extent, and the accession of Diocletian in 284. Irreversible major territorial loss, however, began in 376 with a large - scale irruption of Goths and others. In 395, after winning two destructive civil wars, Theodosius I died, leaving a collapsing field army and the Empire, still plagued by Goths, divided between his two incapable sons. By 476 when Odoacer deposed the Emperor Romulus, the Western Roman Emperor wielded negligible military, political, or financial power and had no effective control over the scattered Western domains that could still be described as Roman. Invading barbarians had established their own power in most of the area of the Western Empire. While its legitimacy lasted for centuries longer and its cultural influence remains today, the Western Empire never had the strength to rise again.
Document 4: Bird migration: The typical image of migration is of northern landbirds, such as swallows (Hirundinidae) and birds of prey, making long flights to the tropics. However, many Holarctic wildfowl and finch (Fringillidae) species winter in the North Temperate Zone, in regions with milder winters than their summer breeding grounds. For example, the pink-footed goose Anser brachyrhynchus migrates from Iceland to Britain and neighbouring countries, whilst the dark-eyed junco Junco hyemalis migrates from subarctic and arctic climates to the contiguous United States and the American goldfinch from taiga to wintering grounds extending from the American South northwestward to Western Oregon. Migratory routes and wintering grounds are traditional and learned by young during their first migration with their parents. Some ducks, such as the garganey Anas querquedula, move completely or partially into the tropics. The European pied flycatcher Ficedula hypoleuca also follows this migratory trend, breeding in Asia and Europe and wintering in Africa.
Document 5: British Isles: Viking invasions began in the 9th century, followed by more permanent settlements, particularly along the east coast of Ireland, the west coast of modern-day Scotland and the Isle of Man. Though the Vikings were eventually neutralised in Ireland, their influence remained in the cities of Dublin, Cork, Limerick, Waterford and Wexford. England however was slowly conquered around the turn of the first millennium AD, and eventually became a feudal possession of Denmark. The relations between the descendants of Vikings in England and counterparts in Normandy, in northern France, lay at the heart of a series of events that led to the Norman conquest of England in 1066. The remnants of the Duchy of Normandy, which conquered England, remain associated to the English Crown as the Channel Islands to this day. A century later the marriage of the future Henry II of England to Eleanor of Aquitaine created the Angevin Empire, partially under the French Crown. At the invitation of a provincial king and under the authority of Pope Adrian IV (the only Englishman to be elected pope), the Angevins invaded Ireland in 1169. Though initially intended to be kept as an independent kingdom, the failure of the Irish High King to ensure the terms of the Treaty of Windsor led Henry II, as King of England, to rule as effective monarch under the title of Lord of Ireland. This title was granted to his younger son but when Henry's heir unexpectedly died the title of King of England and Lord of Ireland became entwined in one person.
Document 6: Bird migration: Orientation behaviour studies have been traditionally carried out using variants of a setup known as the Emlen funnel, which consists of a circular cage with the top covered by glass or wire-screen so that either the sky is visible or the setup is placed in a planetarium or with other controls on environmental cues. The orientation behaviour of the bird inside the cage is studied quantitatively using the distribution of marks that the bird leaves on the walls of the cage. Other approaches used in pigeon homing studies make use of the direction in which the bird vanishes on the horizon.
Document 7: Southern Europe: The Roman Empire came to dominate the entire Mediterranean basin in a vast empire based on Roman law and Roman legions. It promoted trade, tolerance, and Greek culture. By 300 AD the Roman Empire was divided into the Western Roman Empire based in Rome, and the Eastern Roman Empire based in Constantinople. The attacks of the Germanic peoples of northern Europe led to the Fall of the Western Roman Empire in AD 476, a date which traditionally marks the end of the classical period and the start of the Middle Ages.
Document 8: Near East: It has pleased western historians to write of a decline of the Ottoman Empire as though a stable and uncontested polity of that name once existed. The borders did expand and contract but they were always dynamic and always in "question" right from the beginning. The Ottoman Empire was created from the lands of the former eastern Roman Empire on the occasion of the latter's violent demise. The last Roman emperor died fighting hand-to-hand in the streets of his capital, Constantinople, overwhelmed by the Ottoman military, in May, 1453. The victors inherited his remaining territory in the Balkans.
Document 9: Middle Ages: The Emperor Diocletian (r. 284–305) split the empire into separately administered eastern and western halves in 286; the empire was not considered divided by its inhabitants or rulers, as legal and administrative promulgations in one division were considered valid in the other.[C] In 330, after a period of civil war, Constantine the Great (r. 306–337) refounded the city of Byzantium as the newly renamed eastern capital, Constantinople. Diocletian's reforms strengthened the governmental bureaucracy, reformed taxation, and strengthened the army, which bought the empire time but did not resolve the problems it was facing: excessive taxation, a declining birthrate, and pressures on its frontiers, among others. Civil war between rival emperors became common in the middle of the 4th century, diverting soldiers from the empire's frontier forces and allowing invaders to encroach. For much of the 4th century, Roman society stabilised in a new form that differed from the earlier classical period, with a widening gulf between the rich and poor, and a decline in the vitality of the smaller towns. Another change was the Christianisation, or conversion of the empire to Christianity, a gradual process that lasted from the 2nd to the 5th centuries.
Document 10: British Isles: Anglo-Saxons arrived as Roman power waned in the 5th century AD. Initially, their arrival seems to have been at the invitation of the Britons as mercenaries to repulse incursions by the Hiberni and Picts. 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. 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. Ireland had been unaffected by the Romans except, significantly, having been Christianised, traditionally by the Romano-Briton, Saint Patrick. 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. These were later joined by Anglo-Saxon missions of a similar nature.
Document 11: Bird migration: Bewick then describes an experiment which succeeded in keeping swallows alive in Britain for several years, where they remained warm and dry through the winters. He concludes:
Document 12: Bird migration: It was not until the end of the eighteenth century that migration as an explanation for the winter disappearance of birds from northern climes was accepted. Thomas Bewick's A History of British Birds (Volume 1, 1797) mentions a report from "a very intelligent master of a vessel" who, "between the islands of Minorca and Majorca, saw great numbers of Swallows flying northward", and states the situation in Britain as follows:
Document 13: British Isles: The Kingdoms of England and Scotland were unified in 1707 creating the Kingdom of Great Britain. Following an attempted republican revolution in Ireland in 1798, the Kingdoms of Ireland and Great Britain were unified in 1801, creating the United Kingdom. The Isle of Man and the Channel Islands remaining outside of the United Kingdom but with their ultimate good governance being the responsibility of the British Crown (effectively the British government). Although, the colonies of North American that would become the United States of America were lost by the start of the 19th century, the British Empire expanded rapidly elsewhere. A century later it would cover one third of the globe. Poverty in the United Kingdom remained desperate however and industrialisation in England led to terrible condition for the working class. Mass migrations following the Irish Famine and Highland Clearances resulted in the distribution of the islands' population and culture throughout the world and a rapid de-population of Ireland in the second-half of the 19th century. Most of Ireland seceded from the United Kingdom after the Irish War of Independence and the subsequent Anglo-Irish Treaty (1919–1922), with the six counties that formed Northern Ireland remaining as an autonomous region of the UK.
Document 14: Bird migration: The same considerations about barriers and detours that apply to long-distance land-bird migration apply to water birds, but in reverse: a large area of land without bodies of water that offer feeding sites may also be a barrier to a bird that feeds in coastal waters. Detours avoiding such barriers are observed: for example, brent geese Branta bernicla migrating from the Taymyr Peninsula to the Wadden Sea travel via the White Sea coast and the Baltic Sea rather than directly across the Arctic Ocean and northern Scandinavia.
Document 15: British Isles: At the time of the Roman Empire, about two thousand years ago, various tribes, which spoke Celtic dialects of the Insular Celtic group, were inhabiting the islands. The Romans expanded their civilisation to control southern Great Britain but were impeded in advancing any further, building Hadrian's Wall to mark the northern frontier of their empire in 122 AD. At that time, Ireland was populated by a people known as Hiberni, the northern third or so of Great Britain by a people known as Picts and the southern two thirds by Britons.
ground_truth: in 376
sub_queries: Where did this experiment take place? Answer: Britain
Who foreign group conquered Britain around AD 43? Answer: Roman Empire
when did Roman Empire began to fall Answer: in 376