The shrewdest advice I was given on becoming Political Secretary to the Prime Minister in 2016, by a former habitué of Downing Street, was to ‘go for a wander occasionally to see what’s happening elsewhere in the building’. It was advice I followed daily, and which speaks volumes about the charming, chaotic, and too often paranoid atmosphere of the meandering seventeenth-century townhouse which has provided the seat of power for the British Prime Minister since 1732.

Anyone who has had the privilege of working at Number 10 will be alive to the court politics which play such a prominent role in the operation of the building – far more so than in a regular Government Department. ‘Proximity is power’, explains Lord Armstrong of Ilminster, Principal Private Secretary to Edward Heath and Harold Wilson, and Cabinet Secretary under Margaret Thatcher, in the introduction to this well-informed and perceptive book – a maxim I was able to test out during my three years in Downing Street. During my first year there, the Political Office – initially a plucky band of two – was housed where our predecessors had sat, in the old kitchens to the south of the property, previously home to the press office under Press Secretaries including Bernard Ingham and Alastair Campbell. A sudden change to this arrangement was heralded by the arrival of a man with a tape measure shortly after the 2017 general election, measuring up for new desks ahead of our wholly unexpected removal to another part of the building. A small turf war was waged over the summer recess – in hindsight, probably not the most pressing political problem in those sultry weeks, but one which was very satisfactorily resolved with the Political Office restored to its traditional home adjoining the Cabinet Room: a prime location first staked out by Marcia Williams, Political Secretary to Harold Wilson, in 1964, and where it had remained under successive governments until 1997. Jack Brown describes this strategic location with great perspicacity, not least its proximity to a lavatory ‘which can lay claim to having seen more top-level political gossip than any other in the country’.

In recent years, this room had fallen into abeyance as a mere waiting and ad hoc meeting room (readers of Tim Shipman’s contemporary chronicles may have heard of it as the ‘bollocking room’), but previous Political Secretaries had used it – often sharing it with the MP who served as the Prime Minister’s Parliamentary Private Secretary – as a clearing house for political gossip and conversation. Douglas Hurd (1970–74) enticed Cabinet Ministers and others in by allowing smoking within; Richard Ryder (1979–81) installed a fridge from which to serve wine from El Vino. In my own time, enticement came in the form of delicious cakes cooked by the wife of one of my colleagues.

Despite spending most of my waking hours for three years in the building, I learned a great deal I did not know about it from Jack Brown’s informative and highly readable new book on this famous constant of British politics. It is the product of the Number 10 ‘Researcher in Residence’ scheme, established thanks to the late Chris Martin, Principal Private Secretary to David Cameron, 2011–15, who was keen that the history of Downing Street should be properly understood and more widely known. Drawing on archival material, memoirs and biographies of the famous figures who have passed through the famous black door, but also interviews with hidden heroes and heroines of the building – such as the long-serving staff of the Garden Rooms, the all-seeing but discreet front of house team, and the operators of the incomparable telephone service ‘Switch’ – Brown paints a vivid picture of this living and evolving establishment. He keeps his focus tight, concentrating on ten post-war premierships from Attlee to Major, but with ample background on the much longer history of the building. We learn how the number of staff has grown – from 64 in 1970 to 120 by 1997 – yet remains surprisingly small: ‘considerably less than the staff at the disposal of the mayor of a major German city’, in the words of Ferdinand Mount, Head of the Prime Minister’s Policy Unit, 1982–83. I was surprised to discover the long pedigree of the title ‘Chief of Staff’, first bestowed upon Algernon West, a former Private Secretary to Gladstone, in 1892, and mooted as a formal role – with Enoch Powell considered for it – under Macmillan.

No one proof-reads books any longer – both Ken Clarke and Anthony Trollope suffer the excision of the final ‘e’ of their surnames – but this is a carefully constructed, well researched, and insightful book, which shows how a succession of Prime Ministers and their staff have both shaped Number 10 and been shaped by it. It will be read with great interest and enjoyment by people on both sides of that famous front door.