Roman Catholic Diocese of Allegheny


The Diocese of Allegheny is a former Roman Catholic diocese of the United States, in the state of Pennsylvania. It is currently an episcopal titular see, known in Latin as Dioecesis Alleghenensis.

History

The diocese was created on 11 January 1876 with territory split from the Diocese of Pittsburgh, as a fellow suffragan of the Metropolitan Archdiocese of Philadelphia.
Bishop Michael Domenec was appointed as its first ordinary.
When Bishop Domenec died on 29 July 1877, Bishop John Tuigg, who at that time was serving as Bishop of Pittsburgh, was appointed Apostolic Administrator.
On 1 July 1889, the see was suppressed as a residential diocese and its territory was reunited with the diocese of Pittsburgh.

Former territory

At its creation, the Diocese of Allegheny covered eight counties and an area of, leaving the Diocese of Pittsburgh with six counties and an area of. Allegheny County was split unevenly between the two dioceses, with most of that county remaining in the Diocese of Pittsburgh.
The Rev. Andrew Lambing, an early historian of the Catholic Diocese of Pittsburgh, described the boundary lines as follows: