Dialects of Irish
When the old Gaelic order came to an end at the beginning of the 17th century the system of patronage for Irish poets and scholars also declined rapidly. With that the use of a classical standard of written Irish declined as well and in the course of this century traces of dialects appear more and more in Irish documents (Williams 1994: 447). It is certain that Irish had already become dialectally diverse but because of the nature of the textual record, features of the dialects did not show up in writing.
The exclusion of Irish from public life resulted from the Penal Laws, a collective term for anti-Catholic, i.e. anti-Irish, legislation which greatly diminished the standing of the language and its speakers in Irish society. With further developments of the 17th century, notably the campaigns and expulsions by Oliver Cromwell in the late 1640s and early 1650s, language shift from Irish to English began on a wide scale. This was a process which was never to be reversed. Other major demographic events, especially the Great Famine of the 1840s and the subsequent mass emigration, led to a serious drop in the numbers of Irish speakers so that by the late 19th century the Irish-speaking districts were fragmented into three areas, Cork-Kerry, Galway-Mayo and Donegal with a very small enclave in Waterford.