Foras Feasa ar Éirinn

Foras Feasa ar Éirinn - literally "Foundation of Knowledge on Ireland" but most often known in English as "The History of Ireland" - is a narrative history of Ireland by Geoffrey Keating, written in Irish and completed c. 1634. It begins with a preface in which Keating defends the honour of Ireland against the denigrations of writers such as Giraldus Cambrensis, followed by a narrative history in two parts: part one, from the creation of the world to the arrival of Christianity in the 5th century, and part two, from the 5th century to the coming of the Normans in the 12th century.

It depicts Ireland as an autonomous, unitary kingdom of great antiquity. The early part of the work is largely mythical, depicting the history of Ireland as a succession of invasions and settlements, and derives primarily from medieval writings such as the Lebor Gabála Érenn, the Dindsenchas, royal genealogies and stories of heroic kings. The later part depicts the Normans as the latest in this series of settlers. Keating, a Catholic priest of Anglo-Norman descent, gave Irish people of both Gaelic and Anglo-Norman ancestry a shared place in the history of the nation, and emphasised the role of the Church as a unifying factor in Irish society.

The work was extremely popular, surviving in a large number of manuscripts, and its prose style became the standard followed by generations of Irish-language writers. However, it was received critically from the start, with Sir Richard Cox describing it in the 1680s as "an ill-digested heap of very silly fictions". Modern scholars view it in the context of the antiquarian tendency of Renaissance humanism, with Keating expounding on ancient Irish sources, whose authority he defends, to provide "an origin-legend for Counter-Reformation Catholic Ireland."

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