The Roman Catholic Archdiocese of Chicago was established as a diocese in 1843 and as an archdiocese in 1880. It serves more than 2.3 million Catholics in Cook and Lake counties in Northeastern Illinois, a geographic area of 1411 square miles. The archdiocese is divided into six vicariates and 31 deaneries. This local church is headed by the Most Rev. Blase Joseph Cupich, Archbishop of Chicago, assisted by six episcopal vicars, each responsible for a vicariate (region).