DUBLIN — The legal map of Ireland changed Monday in a campaign to promote the country's little-used official tongue, Gaelic, versus its universally spoken rival, English.

A law came into force that strips legal status from English place-names in Ireland's most distant western regions, called the Gaeltacht. In these areas - chiefly the most westerly parts of Counties Cork, Donegal, Galway, Kerry and Mayo and their outlying islands - the government has spent decades funding projects to keep the Irish language alive.

The change affects the names of more than 2,300 towns, villages and crossroads in the Gaeltacht, many of which have long been known both by their Gaelic and English names.

As of Monday, those English names no longer have legal standing and may not be used in government documents or on new Ordnance Survey maps. The switch also applies in a few official Gaelic-speaking pockets of County Meath, northwest of Dublin, and County Waterford in the southeast.

On the Dingle Peninsula in northwest Kerry, for example, two villages known chiefly by their English names, Dunquinn and Ventry, must now be identified on signs and government documents as Dun Chaoin and Ceann Tra.

A second law enacted Monday specifies for the first time the proper Gaelic versions and spellings of hundreds of place-names outside the Gaeltacht, where English has long been dominant. The English versions of these place-names will remain legal, but displaying the Gaelic versions alongside them will become mandatory.

The inconsistent use of English or Gaelic place-names, particularly along the ruggedly beautiful western seaboard of Ireland, has been a source of confusion for tourists for decades. Most maps emphasize the English versions of names, whereas most local road signs are in Gaelic.

Although the new law specifies that the government-run Ordnance Survey must use only Gaelic names in the Gaeltacht area, this does not apply to independent producers of maps. But they are expected to follow the government's new policy.

Tourism officials have argued publicly over whether the switch to exclusively Gaelic signs along the west coast will make it easier or harder for visitors.

The initiative has placed a new focus on the battle to preserve Gaelic in Ireland, where the language faded from everyday use in the 19th century.

Ever since Ireland won independence from Britain in 1922, successive governments have pursued a policy of mandatory Gaelic in schools and made it a requirement for many jobs, even though just 55,000 native Gaelic speakers remain in this country of 3.9 million.

About 40 percent of residents identify themselves as fluent in Gaelic on census forms, but in practice this is not anywhere near the case.

The government's Irish language commissioner, Sean O Cuirreain, reported March 14 that the state was spending €500 million, or $650 million, annually on teaching children Gaelic in elementary and high schools, yet too few students were attaining "a reasonable command of the language" after 13 years and 1,500 hours of instruction. He called for an urgent review of how Gaelic is taught.

English, in practice, permeates even government-funded projects to promote Gaelic. The state-run Gaelic radio network recently decided to begin broadcasting popular music in English, while the state's Gaelic television station runs English-language films.

O Cuirreain noted that the government and opposition lawmakers, though uniformly pro-Gaelic in policy, were demonstrably pro-English in practice - less than 1 percent of parliamentary debates are conducted in Gaelic.