Parliament's upper house now has four members with 'Southwark' in their title after the Bishop of Southwark was introduced to the House of Lords.
26 Church of England bishops serve as Lords Spiritual. Five of the places are reserved for the Archbishops of Canterbury and York and the bishops of the historic dioceses of London, Durham and Winchester.
The remaining 21 seats are filled by the longest-serving diocesan bishops from the rest of the country.
Following the retirement of the Bishop of Oxford in October, the Bishop of Southwark, Rt Revd Christopher Chessun, was the next in turn to join the Lords.
He was introduced to the house on Monday by the Archbishop of York John Sentamu and the Bishop of London Richard Chartres.
Bishop Christopher's arrival in the upper house means that the Lords now has four members with 'Southwark' in their title.
The Conservative Baroness Perry of Southwark has been joined in recent years by Labour's Lord Kennedy of Southwark and Ministry of Sound owner Lord Palumbo of Southwark who takes the Liberal Democrat whip.
The previous Bishop of Southwark, Dr Tom Butler, was a member of the House of Lords between 1996 and 2010.