The pilot episode was due to be recorded at the BBC Television Centre in London, but due to a strike the original sets were very sparsely dressed and production was moved to the BBC Elstree Studios instead. The sets were subsequently improved for the first series. After the pilot was aired and the BBC agreed to a full series, the production team decided to remain at BBC Elstree Studios, and all four series of the show were recorded there. Exterior shots were mostly filmed in and around Diss, Norfolk, for example a disused brush factory which was used as the Union Jack Rubber Company. Other locations include the seafront at Cromer, Lynford Hall and Oxburgh Hall as the bishop's palace. The 1st World War battle scene at the beginning of the pilot episode was built in Long Valley, the British Army's tank training ground in Aldershot. The exterior of the Meldrum house is rarely seen, although the pilot featured exterior shots of an actual building, most probably No. 15, Holland Villas Road, London W14, but later shootings took place at a mockup built on the car park at BBC Elstree Studios or location in Norfolk.