[3] Bishop Egan was previously the Vicar General for the Diocese of Shrewsbury and his appointment was announced by the Holy See on 11 July 2012.

In 1688 the Portsmouth area came under the authority of the Vicar Apostolic of the London District.

On the restoration of the Catholic hierarchy in England and Wales in 1850 Portsmouth became part of the Diocese of Southwark.

On 19 May 1882 the Catholic Diocese of Portsmouth was created, and consists of the counties of Hampshire and Dorset, together with Berkshire and Oxfordshire south of the River Thames, plus the Isle of Wight and the Channel Islands.

[1] In October 2022 it was announced that the diocese was to reduce from 87 parishes to 24 parishes through a programme of church closures and amalgamations; a move prompted in part by falling attendances and a reduction of over 60% in the number of priests.