The toponym "British Isles" refers to a European archipelago comprising Great Britain, Ireland and the smaller, adjacent islands. The word "British" has also become an adjective and demonym referring to the United Kingdom and more historically associated with the British Empire. For this reason, the name British Isles is avoided by some, as such usage could be interpreted to imply continued territorial claims or political overlordship of the Republic of Ireland by the United Kingdom.Studies in Historical Archaeoethnology by Judith Jesch 2003"Geographical terms also cause problems and we know that some will find certain of our terms offensive. Many Irish object to the term the 'British Isles';..." The Dynamics of Conflict in Northern Ireland: Power, Conflict and emancipation. Joseph Ruane and Jennifer Todd. Cambridge University Press. 1996 Diarmaid MacCulloch, The Reformation: Europe's House Divided 1490–1700. (London: Penguin/Allen Lane, 2003): "the collection of islands which embraces England, Ireland, Scotland and Wales has commonly been known as the British Isles. This title no longer pleases all the inhabitants of the islands, and a more neutral description is 'the Atlantic Isles'" (p. xxvi).

On 18 July 2004, The Sunday Business Post questioned the use of British Isles as a purely geographic expression, noting: [The] "Last Post has redoubled its efforts to re-educate those labouring under the misconception that Ireland is really just British. When British Retail Week magazine last week reported that a retailer was to make its British Isles debut in Dublin, we were puzzled. Is not Dublin the capital of the Republic of Ireland?. When Last Post suggested the magazine might see its way clear to correcting the error, an educative e-mail to the publication...: Retrieved 17 July 2006

"... (which) I have called the Atlantic archipelago – since the term 'British Isles' is one which Irishmen reject and Englishmen decline to take quite seriously." Pocock, J. G. A. (2005). "British History: A plea for a new subject". The Discovery of Islands. Cambridge: Cambridge University Press, p. 29. . "... what used to be called the "British Isles", although that is now a politically incorrect term." Finnegan, Richard B.; Edward T. McCarron (2000). Ireland: Historical Echoes, Contemporary Politics. Boulder: Westview Press, p. 358.

"In an attempt to coin a term that avoided the 'British Isles' – a term often offensive to Irish sensibilities – Pocock suggested a neutral geographical term for the collection of islands located off the northwest coast of continental Europe which included Britain and Ireland: the Atlantic archipelago..." Lambert, Peter; Phillipp Schofield (2004). Making History: An Introduction to the History and Practices of a Discipline. New York: Routledge, p. 217.

"..the term is increasingly unacceptable to Irish historians in particular, for whom the Irish Sea is or ought to be a separating rather than a linking element. Sensitive to such susceptibilities, proponents of the idea of a genuine British history, a theme which has come to the fore during the last couple of decades, are plumping for a more neutral term to label the scattered islands peripheral to the two major ones of Great Britain and Ireland." Roots, Ivan (1997). "Union or Devolution in Cromwell's Britain". History Review.The A to Z of Britain and Ireland by Trevor Montague "...although it is traditional to refer to the Republic of Ireland and the United Kingdom of Great Britain and Northern Ireland as the British Isles, when considered as a single archipelago, this nomenclature implies a proprietary title which has long since ceased to exist, if indeed it ever really did exist. Despite the very close affinity between the British and Irish people I have no doubt that my title is both expedient and correct".

Alternative names that are also used for the British Isles include "Britain and Ireland", the "British and Irish Isles", the "Atlantic Archipelago","...(which) I have called the Atlantic archipelago – since the term 'British Isles' is one which Irishmen reject and Englishmen decline to take quite seriously." Pocock, J. G. A. (2006). The Discovery of Islands. Cambridge: Cambridge University Press, p. 29. . the "Anglo-Celtic Isles", the "British-Irish Isles",John Oakland, 2003, British Civilization: A Student's Dictionary, Routledge: London British-Irish Isles, the (geography) see BRITISH ISLES British Isles, the (geography) A geographical (not political or CONSTITUTIONAL) term for ENGLAND, SCOTLAND, WALES, and IRELAND (including the REPUBLIC OF IRELAND), together with all offshore islands. A more accurate (and politically acceptable) term today is the British-Irish Isles. and the Islands of the North Atlantic. In documents drawn up jointly between the British and Irish governments, the archipelago is referred to simply as "these islands".

To some, the reasons to use an alternate name is partly semantic, while, to others, it is a value-laden political one. The Channel Islands are normally included in the British Isles by tradition, even though they are physically a separate archipelago from the rest of the isles.Oxford English Dictionary: "British Isles: a geographical term for the islands comprising Great Britain and Ireland with all their offshore islands including the Isle of Man and the Channel Islands." United Kingdom law uses the term British Islands to refer to the UK, Channel Islands, and Isle of Man as a single collective entity.

An early variant of the term British Isles dates back to Ancient Greek times, when they were known as the Pretanic or Britannic Islands. It was translated as the British Isles into English in the late 16th or early 17th centuries by English and Welsh writers. Whilst early works were straightforward translations of Classical geographies into English, later writings have been described as propaganda and politicised.Salter, F.M.: Edwards, H.L.R., eds, 1955, "The Bibliotheca Historica of Diodorus Siculus translated by John Skelton", Early English Text Society Original Series 233. Vol. 1, p.11.R. J. Mayhew, 2000, "Geography is Twinned with Divinity: The Laudian Geography of Peter Heylyn" in Geographical Review, Vol. 90, No. 1 (January 2000), pp. 18–34: "In the period between 1600 and 1800, politics meant what we might now term 'high politics', excluding the cultural and social elements that modern analyses of ideology seek to uncover. Politics referred to discussions of dynastic legitimacy, of representation, and of the Constitution. ...

Geography books spanning the period from the Reformation to the Reform Act ... demonstrated their authors' specific political identities by the languages and arguments they deployed. This cannot be seen as any deviation from the classical geographical tradition, or as a tainting of geography by politics, because geography was not to be conceived separately from politics."Robert Mayhew, 2005, "" in the British Journal of the History of Science, 38(1): 73–92, March 2005.

The term became controversial after the breakup of the United Kingdom of Great Britain and Ireland in 1922. The names of the archipelago's two sovereign states were themselves the subject of a long dispute between the Irish and British governments.

History

Classical Antiquity The earliest known names for the islands come from Greco-Roman writings. Sources included the Massaliote Periplus (a merchants' handbook from around 500 BC describing sea routes) and the travel writings of the Greek, Pytheas, from around 320 BC., The Massaliote Periplus describes a sea route south round the west coast of Spain from the promontory of Oestriminis (Cape Finisterre) back to the Mediterranean. The poem by Avienius makes used of it in describing the voyage of Himilco the Navigator, also incorporating fragments from 11 ancient writers including Pytheas. When Avienus says it's two days sailing from Oestriminis to the Holy Isle, inhabited by the Hierni, near Albion, this differs from the sailing directions of the Periplus and implies that Oestriminis is Brittany, a conflict explained if it had been taken by Avienus from one of his other sources. Although the earliest texts have been lost, excerpts were quoted or paraphrased by later authors. The main islands were called "Ierne", equal to the term Ériu for Ireland, and "Albion" for present-day Great Britain. The island group had long been known collectively as the Pretanic or Britanic isles.

There is considerable confusion about early use of these terms and the extent to which similar terms were used as self-description by the inhabitants. Cognates of these terms are still in use.<ref>Cognates of Albion (normally referring only to Scotland) – Albion (archæic); ; ; ; ; ; . Cognates of Ierne – Ireland; ; ; ; ; ; though in English Albion is deliberately archæic or poetical. Cognates of Priteni – ; Briton and British'.</ref>

According to T. F. O'Rahilly in 1946 "Early Greek geographers style Britain and Ireland 'the Pretanic (or Brettanic) islands', i.e. the islands of the Pritani or Priteni" and that "From this one may reasonably infer that the Priteni were the ruling population of Britain and Ireland at the time when these islands first became known to the Greeks". O'Rahilly identified the Preteni with the and the , whom he stated were the earliest of the "four groups of Celtic invaders of Ireland" and "after whom these islands were known to the Greeks as 'the Pretanic Islands'". Today O'Rahilly's historical views on the Preteni and the ethnic makeup of early Ireland are no longer accepted by academic archeologists and historians.

According to A. L. F. Rivet and Colin Smith in 1979 "the earliest instance of the name which is textually known to us" is in The Histories of Polybius, who referred to them . According to Rivet and Smith, this name encompassed "Britain with Ireland". Polybius wrote:

According to Christopher Snyder in 2003, the collective name "Brittanic Isles" () was "a geographic rather than a cultural or political designation" including Ireland. According to Snyder, "Preteni", a word related to the and to the , was used by southern Britons to refer to the people north of the Antonine Wall, also known as the Picts (). According to Snyder, "Preteni" was a probably from a Celtic term meaning "people of the forms", whereas the Latin name was probably derived from the Celtic practice of tattooing or painting the body before battle. According to Kenneth H. Jackson, the Pictish language was a Celtic language related to modern Welsh and to ancient Gaulish with influences from earlier non-Indo-European languages.

The fourth chapter of the first book of the of Diodorus Siculus describes Julius Caesar as having "advanced the Roman Empire as far as the British Isles" () and in the 38th chapter of the third book Diodorus remarks that the region "about the British Isles" () and other distant lands of the oecumene "have by no means come to be included in the common knowledge of men". According to Philip Freeman in 2001, "it seems reasonable, especially at this early point in classical knowledge of the Irish, for Diodorus or his sources to think of all inhabitants of the Brettanic Isles as Brettanoi".'''