Westminster Cathedral
The site on which the cathedral stands in the City of Westminster was purchased by the Diocese of Westminster in 1885, and construction was completed in 1903. Westminster Cathedral is the largest Catholic church building in England and Wales and the seat of the Archbishop of Westminster.
Westminster Abbey
Westminster diocese was dissolved in 1550, but the abbey was recognised (in 1552, retroactively to 1550) as a second cathedral of the Diocese of London until 1556. The already-old expression "robbing Peter to pay Paul" may have been given a new lease of life when money meant for the abbey, which is dedicated to Saint Peter, was diverted to the treasury of St Paul's Cathedral.
The abbey was restored to the Benedictines under the Catholic Mary I of England, but they were again ejected under Elizabeth I in 1559. In 1560, Elizabeth re-established Westminster as a "Royal Peculiar" – a church of the Church of England responsible directly to the Sovereign, rather than to a diocesan bishop – and made it the Collegiate Church of St Peter (that is, a non-cathedral church with an attached chapter of canons, headed by a dean.)