On this Wikipedia the language links are at the top of the page across from the article title. For the shared literary form that irish corned beef and cabbage stew in use from the 13th century to the 16th-18th centuries, see Classical Gaelic.

This article contains IPA phonetic symbols. With a writing system, Ogham, dating back to at least the 4th century AD, which was gradually replaced by Latin script since the 5th century AD, Irish has the oldest vernacular literature in Western Europe. Goidelic, used to refer to the language family, is derived from the Old Irish term. Gaelic of Scotland and the Isle of Man, as well as of Ireland. Irish, as well as Gaelic and Irish Gaelic. Goidelic is a synonym of Gaelic, used mainly in linguistic typology and historical linguistics. Goidelic and Brittonic together constitute the Insular Celtic languages.

4th century AD, a stage of the language known as Primitive Irish. These writings have been found throughout Ireland and the west coast of Great Britain. Primitive Irish underwent a change into Old Irish through the 5th century. By the 10th century, Old Irish had evolved into Middle Irish, which was spoken throughout Ireland, Isle of Man and parts of Scotland. It is the language of a large corpus of literature, including the Ulster Cycle. Early Modern Irish, dating from the 13th century, was the basis of the literary language of both Ireland and Gaelic-speaking Scotland. Modern Irish, as attested in the work of such writers as Geoffrey Keating, may be said to date from the 17th century, and was the medium of popular literature from that time on.

From the 18th century on, the language lost ground in the east of the country. Discouragement of its use by the Anglo-Irish administration. The Catholic church supported the use of English over Irish. The spread of bilingualism from the 1750s onwards. By the mid-18th century, English was becoming a language of the Catholic middle class, the Catholic Church and public intellectuals, especially in the east of the country. Irish was not marginal to Ireland’s modernisation in the 19th century, as is often assumed.

In the first half of the century there were still around three million people for whom Irish was the primary language, and their numbers alone made them a cultural and social force. Irish was also common in commercial transactions. This linguistic dynamism was reflected in the efforts of certain public intellectuals to counter the decline of the language. At the end of the 19th century, they launched the Gaelic revival in an attempt to encourage the learning and use of Irish, although few adult learners mastered the language. Efforts were also made to develop journalism and a modern literature. Although it has been noted that the Catholic Church played a role in the decline of the Irish language before the Gaelic Revival, the Protestant Church of Ireland also made only minor efforts to encourage use of Irish in a religious context.