The population of Ireland is predominantly of Celtic origin. No significant ethnic minorities exist. The population decreased from the 1840s, when about 6.5 million persons lived in the area included in the republic, until about 1970, largely because of a high emigration rate. For administrative purposes, Ireland is divided into 27 counties, most of which are described in separate articles, and 5 county boroughs, which are coextensive with the cities of Dublin, Cork, Galway, Limerick, and Waterford. Cork is the second largest city and a major port, with a population of 173,694.
Freedom of worship is guaranteed by the constitution.
Almost all the people speak English, and about one-fourth also speak Irish, a Gaelic language that is the traditional tongue of Ireland. Irish is spoken as the vernacular by a relatively small number of people, however, mostly in areas of the west. The constitution provides for both Irish and English as official languages. Education Irish influence on Western education began 14 centuries ago. From the 6th to the 8th century, when western Europe was largely illiterate, nearly 1000 Irish missionaries traveled to England and the Continent to teach Christianity.