sentences:  Erected as the Diocese of Mercedes on 20 April 1934, it was renamed as the Diocese of Mercedes-Luján on 10 May 1989 and elevated on 21 November 1997.Its mother church is the Catedral Basílica de Mercedes-Luján in Mercedes.On Friday, March 4, 2019, Pope Francis raised it to a metropolitan archdiocese, with three suffragan dioceses- two had been part of the La Plata Province and one had been part of the Buenos Aires Province.