In 2024, film-makers brought the final preparations for D-Day to Mentmore Towers. For Pressure, the Buckinghamshire mansion became the screen setting for Southwick House in Hampshire, where senior Allied commanders faced the decision to launch the Normandy landings.
The connection gives a familiar regional landmark an unexpected role in a story of international importance. Mentmore’s own wartime history concerned the protection of national collections. Its appearance as a command centre is a later chapter, created for the cinema.
A weather forecast at the centre of the drama
Released in 2026, Pressure concentrates on the days before D-Day. Its central figure is Group Captain James Stagg, responsible for bringing meteorological advice to General Dwight D. Eisenhower and the Allied command.
The film was directed by Anthony Maras, who adapted David Haig’s stage play with Haig. Its principal cast brings together the advisers and commanders whose competing judgements shape the drama.
| Actor | Role |
| Andrew Scott | Group Captain James Stagg, chief meteorological adviser |
| Brendan Fraser | General Dwight D. Eisenhower, Supreme Allied Commander |
| Kerry Condon | Kay Summersby, Eisenhower’s aide |
| Damian Lewis | Bernard Montgomery |
| Chris Messina | Irving Krick, the American meteorologist |
The subject offers an unusual perspective on a familiar military event. Here, the immediate problem is whether a forecast can give commanders sufficient confidence to commit an invasion force. Scientific advice must be delivered clearly under enormous pressure, while the responsibility for acting on it rests with Eisenhower.
Bringing the production to Mentmore
A 2024 planning submission covered temporary filming at Mentmore Towers, its grounds and St Mary’s Church. Its proposed timetable ran from preparation in August through filming in September and October, followed by clearance in November.
Contemporary reporting named Mentmore as a filming location when production began in Britain in September 2024. The estate was taking on another temporary identity: rooms familiar as part of a Victorian country house would become the interiors of a wartime command centre.
The mansion’s large interiors and distinctive hall supplied a setting with the scale and architectural character of a substantial headquarters. On screen, however, it represents a building elsewhere. The film’s geography should not be confused with the location of the historical events.
The real Southwick House
Southwick House stands near Portsmouth. It became a centre for the senior Allied commanders during the final preparations for the invasion, bringing the weather briefings and military decisions together close to the embarkation area.
The historic wall map used in planning the landings is preserved there. It records the Channel, the Normandy coastline and the routes of the operation: a physical reminder of the decisions represented in the film. Defence Infrastructure Organisation accounts describe the house’s central role in the D-Day preparations.
Mentmore and Southwick therefore have different histories linked by the production. One supplied the screen location; the other supplied the historical setting.
The decision to delay—and then proceed
The landings had been planned for 5 June 1944. As that date approached, unsettled Atlantic weather brought deteriorating conditions. Stagg advised that the forecast was too poor, and Eisenhower deferred the operation.
The next question was whether 6 June would offer a usable opening. Stagg and the forecasting teams identified a brief improvement. They were offering a marginal weather window rather than a promise of settled conditions.
| Date | What was at stake |
| 4 June 1944 | The worsening forecast led to postponement of the planned 5 June landings. |
| 5 June 1944 | A forecast of sufficient improvement allowed the final decision to proceed for the following day. |
| 6 June 1944 | Allied forces landed in Normandy. |
The short sequence conveys the central dilemma. Waiting reduced some immediate weather risks but prolonged uncertainty and threatened the secrecy of a vast operation. Proceeding committed people and equipment to conditions that were still far from ideal.
History and dramatic interpretation
The Met Office’s assessment of Pressure recognises the film’s portrayal of the stakes and forecasting disagreements, while explaining some dramatic compression. Stagg had been appointed to his D-Day forecasting role in November 1943; he was not brought into the task only three days before the invasion.
Nor was every disagreement conducted by people gathered in one room. Forecasting teams worked from different centres and exchanged information through telephone and teleprinter communications. Bringing characters together makes those exchanges easier to follow on screen.
The production consulted the Met Office’s archive for maps and documents. That attention to period detail sits alongside the choices required to turn a complex forecasting operation into a drama. Reading the film with its historical sources adds another layer to the story.
For the mansion’s history, including its very different Second World War role, see Mentmore Towers. Its place among neighbouring family estates is explored in The Rothschild Landscape.
Sources and further reading
Buckinghamshire filming planning submission, 2024
Defence Infrastructure Organisation: Southwick and D-Day