[1] The see is in the town of Northampton where the bishop's seat is located in the Cathedral Church of Our Lady and Saint Thomas of Canterbury.
The Eastern District consisted of the counties of Cambridgeshire (with the Isle of Ely), Huntingdonshire, Lincolnshire, Norfolk, Northamptonshire, Rutland, and Suffolk, all from the former Midland District, and the counties of Bedfordshire and Buckinghamshire from the London District.
[2] On the restoration of the Catholic hierarchy in England and Wales by Pope Pius IX in 1850, most of the Eastern District became the Diocese of Northampton,[3] with the Vicar Apostolic the Eastern District, William Wareing, appointed the first bishop of the diocese.
[4] The remainder of the Eastern District (Lincolnshire and Rutland) became part of the Diocese of Nottingham.
[5] Through the Local Government Act of 1972, a small area of Buckinghamshire became part of Berkshire, and Huntingdonshire and the Isle of Ely merged into Cambridgeshire.