Petre continued to purchase others property and to extend his house over a number of years.
[1] Over the years Petre House was extended across the parish boundary into the former close of St Bartholomew's priory.
During the Comonwealth the house was used as a prison and it was here in 1646 that Michael Hudson was imprisoned while being questioned by a Parliamentary committee about the flight of Charles I from Oxford to Newark-upon-Trent.
Shortly after the non-juror, Thomas Rawlinson ("Tom Folio"), removed his great library to London House, where he died in 1725.
Bishop Sherlock, in 1749, obtained parliamentary power to dispose of London House for the benefit of the See.