Ireland, Church of, Anglican church of both the Republic of Ireland and Northern Ireland. As a separate body the church goes back to the Reformation when the Irish church was officially reformed along the same lines as the church in England (see England, Church of). But the effects of the Reformation were superficial in Ireland and the Church of Ireland has always included only a small portion of the Irish population. It was disestablished as the state church in 1869. The church has about 410,000 members (1999), with its main strength in Northern Ireland.