Question: When did the land bridge disappear between Britain and the country associated with a harp, as the country where Queen Margaret and her son traveled is associated with a lion?

full_context: Document 1: Europe: This description is simplified. Sub-regions such as the Iberian Peninsula and the Italian Peninsula contain their own complex features, as does mainland Central Europe itself, where the relief contains many plateaus, river valleys and basins that complicate the general trend. Sub-regions like Iceland, Britain, and Ireland are special cases. The former is a land unto itself in the northern ocean which is counted as part of Europe, while the latter are upland areas that were once joined to the mainland until rising sea levels cut them off.
Document 2: Union Jack: The Union Jack, or Union Flag, is the national flag of the United Kingdom. The flag also has an official or semi-official status in some other Commonwealth realms: for example, it is a ceremonial flag in Canada by parliamentary resolution, and known there as the Royal Union Flag. Further, it is used as an official flag in some of the smaller British overseas territories. The Union Flag also appears in the canton (upper left - hand quarter) of the flags of several nations and territories that are former British possessions or dominions, as well as the state flag of Hawaii.
Document 3: Wars of Scottish Independence: The war began in earnest with Edward I's brutal sacking of Berwick in March 1296, followed by the Scottish defeat at the Battle of Dunbar and the abdication of John Balliol in July. The English invasion campaign had subdued most of the country by August and, after removing the Stone of Destiny from Scone Abbey and transporting it to Westminster Abbey, Edward convened a parliament at Berwick, where the Scottish nobles paid homage to him as King of England. Scotland had been all but conquered.
Document 4: John, King of England: In the late 12th and early 13th centuries the border and political relationship between England and Scotland was disputed, with the kings of Scotland claiming parts of what is now northern England. John's father, Henry II, had forced William the Lion to swear fealty to him at the Treaty of Falaise in 1174. This had been rescinded by Richard I in exchange for financial compensation in 1189, but the relationship remained uneasy. John began his reign by reasserting his sovereignty over the disputed northern counties. He refused William's request for the earldom of Northumbria, but did not intervene in Scotland itself and focused on his continental problems. The two kings maintained a friendly relationship, meeting in 1206 and 1207, until it was rumoured in 1209 that William was intending to ally himself with Philip II of France. John invaded Scotland and forced William to sign the Treaty of Norham, which gave John control of William's daughters and required a payment of £10,000. This effectively crippled William's power north of the border, and by 1212 John had to intervene militarily to support the Scottish king against his internal rivals.[nb 16] John made no efforts to reinvigorate the Treaty of Falaise, though, and both William and Alexander remained independent kings, supported by, but not owing fealty to, John.
Document 5: British Isles: Many larger animals, such as wolf, bear and the European elk are today extinct. However, some species such as red deer are protected. Other small mammals, such as rabbits, foxes, badgers, hares, hedgehogs, and stoats, are very common and the European beaver has been reintroduced in parts of Scotland. Wild boar have also been reintroduced to parts of southern England, following escapes from boar farms and illegal releases. Many rivers contain otters and seals are common on coasts. Over 200 species of bird reside permanently and another 200 migrate. Common types are the common chaffinch, common blackbird, house sparrow and common starling; all small birds. Large birds are declining in number, except for those kept for game such as pheasant, partridge, and red grouse. Fish are abundant in the rivers and lakes, in particular salmon, trout, perch and pike. Sea fish include dogfish, cod, sole, pollock and bass, as well as mussels, crab and oysters along the coast. There are more than 21,000 species of insects.
Document 6: Elizabeth Woodville: Now referred to as Dame Elizabeth Grey, she and the Duke of Buckingham (a former close ally of Richard III and now probably seeking the throne for himself) now allied themselves with Lady Margaret Stanley (née Beaufort) and espoused the cause of Margaret's son Henry Tudor, a great-great-great-grandson of King Edward III, the closest male heir of the Lancastrian claim to the throne with any degree of validity. To strengthen his claim and unite the two feuding noble houses, Elizabeth Woodville and Margaret Beaufort agreed that the latter's son should marry the former's eldest daughter, Elizabeth of York, who upon the death of her brothers became the heiress of the House of York. Henry Tudor agreed to this plan and in December 1483 publicly swore an oath to that effect in the cathedral in Rennes, France. A month earlier, an uprising in his favour, led by Buckingham, had been crushed.
Document 7: British Isles: Few species of reptiles or amphibians are found in Great Britain or Ireland. Only three snakes are native to Great Britain: the common European adder, the grass snake and the smooth snake; none are native to Ireland. In general, Great Britain has slightly more variation and native wild life, with weasels, polecats, wildcats, most shrews, moles, water voles, roe deer and common toads also being absent from Ireland. This pattern is also true for birds and insects. Notable exceptions include the Kerry slug and certain species of wood lice native to Ireland but not Great Britain.
Document 8: Coat of arms of the Netherlands: The coat of arms of the Kingdom of the Netherlands was originally adopted in 1815 and later modified in 1907. The arms are a composite of the arms of the former Dutch Republic and the arms of the House of Nassau, it features a checkered shield with a lion grasping a sword in one hand and a bundle of arrows in the other and is the heraldic symbol of the monarch (King Willem-Alexander) and the country. The monarch uses a version of the arms with a mantle () while the government of the Netherlands uses a smaller version without the mantle (cloak) or the pavilion, sometimes only the shield and crown are used (). The components of the coats of arms were regulated by Queen Wilhelmina in a royal decree of 10 July 1907, affirmed by Queen Juliana in a royal decree of 23 April 1980.
Document 9: Monarchy of the United Kingdom: The Royal coat of arms of the United Kingdom are "Quarterly, I and IV Gules three lions passant guardant in pale Or [for England]; II Or a lion rampant within a double tressure flory-counter-flory Gules [for Scotland]; III Azure a harp Or stringed Argent [for Ireland]". The supporters are the Lion and the Unicorn; the motto is "Dieu et mon droit" (French: "God and my Right"). Surrounding the shield is a representation of a Garter bearing the motto of the Chivalric order of the same name; "Honi soit qui mal y pense". (Old French: "Shame be to him who thinks evil of it"). In Scotland, the monarch uses an alternative form of the arms in which quarters I and IV represent Scotland, II England, and III Ireland. The mottoes are "In Defens" (an abbreviated form of the Scots "In My Defens God Me Defend") and the motto of the Order of the Thistle; "Nemo me impune lacessit". (Latin: "No-one provokes me with impunity"); the supporters are the unicorn and lion, who support both the escutcheon and lances, from which fly the flags of Scotland and England.
Document 10: Climate of the British Isles: The British Isles undergo very small temperature variations. This is due to its proximity to the Atlantic, which acts as a temperature buffer, warming the Isles in winter and cooling them in summer. Coastal areas tend to be more temperate than inland areas, as the influence of the ocean is less acute. Valleys can be especially cold, as cool air collects in them during the winter. July is usually the warmest month, with the highest temperatures being found closest to Continental Europe, in south - east England. Temperatures usually do not reach freezing points, especially in coastal areas. However, the temperature is mainly warm to mediate temperatures.
Document 11: Wars of the Roses: Queen Margaret and her son had fled to north Wales, parts of which were still in Lancastrian hands. They later travelled by sea to Scotland to negotiate for Scottish assistance. Mary of Gueldres, Queen Consort to James II of Scotland, agreed to give Margaret an army on condition that she cede the town of Berwick to Scotland and Mary's daughter be betrothed to Prince Edward. Margaret agreed, although she had no funds to pay her army and could only promise booty from the riches of southern England, as long as no looting took place north of the River Trent.
Document 12: Elizabeth II: From 21 April 1944 until her accession, Elizabeth's arms consisted of a lozenge bearing the royal coat of arms of the United Kingdom differenced with a label of three points argent, the centre point bearing a Tudor rose and the first and third a cross of St George. Upon her accession, she inherited the various arms her father held as sovereign. The Queen also possesses royal standards and personal flags for use in the United Kingdom, Canada, Australia, New Zealand, Jamaica, Barbados, and elsewhere.
Document 13: British Isles: The islands enjoy a mild climate and varied soils, giving rise to a diverse pattern of vegetation. Animal and plant life is similar to that of the northwestern European continent. There are however, fewer numbers of species, with Ireland having even less. All native flora and fauna in Ireland is made up of species that migrated from elsewhere in Europe, and Great Britain in particular. The only window when this could have occurred was between the end of the last Ice Age (about 12,000 years ago) and when the land bridge connecting the two islands was flooded by sea (about 8,000 years ago).
Document 14: John, King of England: The rebels made the first move in the war, seizing the strategic Rochester Castle, owned by Langton but left almost unguarded by the archbishop. John was well prepared for a conflict. He had stockpiled money to pay for mercenaries and ensured the support of the powerful marcher lords with their own feudal forces, such as William Marshal and Ranulf of Chester. The rebels lacked the engineering expertise or heavy equipment necessary to assault the network of royal castles that cut off the northern rebel barons from those in the south. John's strategy was to isolate the rebel barons in London, protect his own supply lines to his key source of mercenaries in Flanders, prevent the French from landing in the south-east, and then win the war through slow attrition. John put off dealing with the badly deteriorating situation in North Wales, where Llywelyn the Great was leading a rebellion against the 1211 settlement.
Document 15: East India Company: The East India Company's arms, granted in 1698, were: "Argent a cross Gules; in the dexter chief quarter an escutcheon of the arms of France and England quarterly, the shield ornamentally and regally crowned Or." The crest was: "A lion rampant guardant Or holding between the forepaws a regal crown proper." The supporters were: "Two lions rampant guardant Or, each supporting a banner erect Argent, charged with a cross Gules." The motto was AUSPICIO REGIS ET SENATUS ANGLIÆ (Latin: By right of the King and the Senate of England).
ground_truth: about 8,000 years ago
sub_queries: Where do they travel to? Answer: Scotland
A lion is to Scotland as a stringed agent is to? Answer: Ireland
When did the land bridge between Ireland and Britain disappear? Answer: about 8,000 years ago