The restructuring, announced by the Papal Nuncio to Ireland, marks the biggest change in diocesan structures since the 12th century and reflects Ireland’s shrinking Catholic population. The diocese of Achonry, for instance, has 23 parishes, catering to a Catholic population of less than 40,000. In sharp contrast, the U.S. Archdiocese of Los Angeles, with a Catholic population of more than 4 million, is served by one archbishop and six auxiliaries. This is roughly equivalent to all the Catholics in Ireland.