The Roman Catholic Diocese of Bardstown (Kentucky) was established on April 8, 1808, along with the dioceses of Boston, New York, and Philadelphia, out of the territory of the Baltimore Diocese, the first Catholic diocese in the US. When founded, the Bardstown Diocese included most of Kentucky, Tennessee, Missouri, Illinois, Indiana, Ohio and Michigan. The geographical area was large, and today there are 44 dioceses in the area comprising the original diocese.
Benedict Joseph Flaget was the first Bishop of Bardstown. He was briefly succeeded by John Baptist Mary David who resigned less than a year later, when Flaget was again appointed to head the diocese. The historic Basilica of Saint Joseph Proto-Cathedral, the former cathedral of the Diocese of Bardstown, is now a parish church.
The Diocese of Bardstown established its first church, Saint Thomas Parish, within four years of its founding. The diocese eventually increased the number of parishes to 23, and the number of priests from six to 36 within the first 25 years of its founding.
In 1841, the Diocese was transferred from Bardstown to Louisville and was renamed the Diocese of Louisville with its Cathedral of the Assumption. Later it was raised to Archdiocese of Louisville. The Diocese of Bardstown, no longer a residential bishopric, is today listed by the Catholic Church as a titular see.