The Celtic or Keltic languages (usually pronounced /ˈkɛltɪk/ but sometimes /ˈsɛltɪk/) are descended from Proto-Celtic, or "Common Celtic"; a branch of the greater Indo-European language family. The term "Celtic" was first used to describe this language group by Edward Lhuyd in 1707.

Celtic languages are most commonly spoken on the north-western edge of Europe, notably in Ireland, Scotland, Wales, Brittany, Cornwall, and the Isle of Man, and can be found spoken on Cape Breton Island. There are also a substantial number of Welsh speakers in the Patagonia area of Argentina. Some people speak Celtic languages in the other Celtic diaspora areas of the United States, Canada, Australia, and New Zealand. In all these areas, the Celtic languages are now only spoken by minorities though there are continuing efforts at revitalization.

During the 1st millennium BC, they were spoken across Europe, in the Iberian Peninsula, from the Atlantic and North Sea coastlines, up the Rhine valley and down the Danube valley to the Black Sea, the Upper Balkan Peninsula, and in Galatia in Asia Minor. The spread to Cape Breton and Patagonia occurred in modern times. Celtic languages were spoken in Australia before federation in 1901.

Sir Barrington Windsor Cunliffe, CBE, known professionally as Barry Cunliffe (born 10 December 1939) is a former Professor of European Archaeology at the University of Oxford, a position held from 1972 to 2007. He is now Emeritus Professor of European Archaeology.

Cunliffe's decision to become an archaeologist was sparked off at the age of nine by the discovery of Roman remains on his uncle's farm in Somerset. After studying at Portsmouth Northern Grammar School (now the Mayfield School) and reading archaeology and anthropology at the University of Cambridge, he became a lecturer at the University of Bristol in 1963. Fascinated by the Roman remains in nearby Bath he threw himself into a programme of excavation and publication.

In 1966 he became an unusually young professor when he took the chair at the newly-founded Department of Archaeology at the University of Southampton. There he became involved in the excavation (1961–68) of the Fishbourne Roman Palace in Sussex. Another site in southern England led him away from the Roman period. He began a long series of summer excavations (1969–88) of the Iron Age hill fort at Danebury, Hampshire and was subsequently involved in the Danebury Environs Programme (1989–95). His interest in Iron Age Britain and Europe generated a number of publications and he became an acknowledged authority on the Celts,

Brian Stowell (born 6 September 1936) is a Manx radio personality, linguist and author. He is considered one of the primary people behind the revival of the Manx language. While a student he became fluent in the language, and made tape recordings of its elderly speakers. He became fluent in Irish and used his fluency to translate Irish language courses into Manx use. He has become involved with radio broadcasts for Manx Radio.

On Tynwald Day 2010, Dr Stowell was awarded the Tynwald Honour, the highest honour that Tynwald can award a citizen.

Brian Stowell published Contoyryssyn Ealish ayns Cheer ny Yindyssyn, a Manx translation of Alice's Adventures in Wonderland, in 1990. In March 2006 Stowell's Dunveryssyn yn Tooder-Folley (The Vampire Murders), the first full-length novel in Manx, was published.

The Indo-Iranian language group constitutes the easternmost extant branch of the Indo-European family of languages. It consists of three language groups: the Indo-Aryan, Iranian and Nuristani. The Indo-Iranian languages occasionally go by the term "Aryan languages." The speakers of the Proto-Indo-Iranian language, the hypothetical Proto-Indo-Iranians, are usually associated with the late 3rd millennium BC Andronovo and Sintashta-Petrovka cultures of Central Asia. Their expansion is believed to have been connected with the invention of the chariot.

The contemporary Indo-Iranian languages form the largest sub-branch of Indo-European, with more than one billion speakers in total, stretching from Europe (Romani) and the Caucasus (Ossetian) eastward to Xinjiang (Sarikoli) and Assam (Assamese) and south to Sri Lanka (Sinhalese). SIL in a 2005 estimate counts a total of 308 varieties, the largest in terms of native speakers being Hindustani (Hindi and Urdu, ca. 190-330 million), Bengali (ca. 190 million), Punjabi (ca. 88 million), Marathi (ca. 70 million), Persian (ca. 70 million), Pashto (ca. 50 million), Gujarati (ca. 46 million), Kurdish (ca. 16-30 million), Bhojpuri (ca. 35 million), Awadhi (ca. 35 million), Maithili (ca. 35 million), Oriya (ca. 32 million), Marwari (ca. 31 million), Sindhi (ca. 21 million), Rajasthani (ca. 20 million), Chhattisgarhi (ca. 17 million), Assamese (ca. 17 million), Sinhalese (ca. 16 million), and Rangpuri (ca. 15 million).