Classical Gaelic

Classical Gaelic
Native to	Scotland
Era	13th to 18th century Archaic literary language based on 12th century Irish, formerly used by professional classes in Ireland until the 17th century, and Scotland until the 18th century.
Language family	Indo-European Celtic Insular Celtic Goidelic Classical Gaelic
Early forms	Primitive Irish Old Irish Middle Irish
Writing system	Latin
Language codes
ISO 639-3
Glottolog	hibe1235

13th to 18th century

Classical Gaelic (Scottish Gaelic: Gàidhlig Chlasaigeach; Irish: Gaeilge Chlasaiceach) was the shared literary form that was in use in Scotland and Ireland from the 13th to the 18th centuries. The language may be thought of as a high-register version of Early Modern Irish. Although the first written signs of Scottish Gaelic having diverged from Irish appear as far back as the 12th century annotations of the Book of Deer, Scottish Gaelic did not have a standardised form and did not appear in print on a significant scale until the 1767 translation of the New Testament into Scottish Gaelic—though John Carswell's Foirm na n-Urrnuidheadh, an adaptation of John Knox's Book of Common Order, was the first book printed in either Scottish or Irish Gaelic.

Ethnologue gives the name "Hiberno-Scottish Gaelic" (and the ISO 639-3 code ghc) as a cover term for Classical Gaelic and Early Modern Irish.

...
Wikipedia