There have been several histories of Harrow school written by masters or Old Harrovians, but more than half a century has passed since the last one (by E D Laborde in 1947). Tyerman’s book is the first to be based on unfettered access to the governors’ archives as well as a wide range of rarely used sources. The result is an excellent and definitive study of the shifting circumstances of the school over six centuries.

The author, a senior tutor at Harrow, gives an objective account of the rise of the institution from small grammar to leading public school, drawing its pupils, even at the beginning of the last century, from overseas (Nehru, the prime minister of India, was a scholar from 1905 to 1907).

From the time of its creation in 1615 (it seems there was a school before 1615 and the book has the subtitle “1324-1991”) for the education of 30 poor boys by the benefaction of a local worthy, John Lyon, the school had wider aspirations. By the end of the 17th century, more than one in three pupils were “foreigners”. This was achieved by a long-running campaign by successive governors to exclude locals, culminating in the establishment of a separate Lower or Under School of John Lyon in 1876.

Eton was not only its friendly rival but role model and a source of headmasters. One, old Etonian, Thomas Thackeray, was directed by the Harrow governors in 1753 to educate scholars “in every respect in the same manner as is observed in Eton school”. By appointing schoolmasters of high academic attainment, Harrow secured pupils of substance and quality.

Upward mobility continued - in 1803, the school could boast of three prospective dukes, one marquess, seven earls and viscounts and four lords, a total of 41 peers, representing 12 per cent of the school population. The golden age of the school was under the headmastership of Joseph Drury (1785-1805). During his time there, he taught five of the seven prime ministers the school has produced.

One of the more fascinating aspects of the book is Tyerman’s account of the influence of successive headmasters. (The practice of appointing clerical heads continued until 1925 and the ability to teach classics was a necessary qualification until as late as 1980.) Dynastic links were established, such as the Butlers: George (1805-28) and later his son, Montagu (1860-85). On the other hand, Montagu Butler was the only Old Harrovian to date to become headmaster, and since 1805, except for a brief period in the Second World War, no member of staff at the school has been promoted to head.

Tyerman’s judgments on some headmasters are less flattering. For exmple, Cyril Norwood never got to grips with the job and was absent for long periods attending meetings as chairman of the Secondary School Examinations Council. The dismissal of an earlier head, Charles Vaughan, for an alleged affair with a pupil, the author believes, after weighing the evidence, was justified.

One of the themes in the book is the tensions between housemasters and heads - sometimes it could be productive but it could also lead to paralysis, and, in some cases, open warfare.

Academically, the school aimed over the centuries at producing gentlemen rather than scholars. It was taken for granted that classics provided good mental training for many who would not have to contemplate future occupations.

Nevertheless, unlike many other public schools, Harrow did not shun innovation. A modern side, offering a range of arts subjects, was established in 1869 in response to the Clarendon Commission’s report on public school reform. Winston Churchill, perhaps the school’s most famous pupil, if not byron, was poor at Latin and was diverted into the Army Side.

Harrow readily allowed government inspectors in, even if Eton resisted until 1938. The ClassicsModern Side dichotomy was abolished in 1917 and Harrow was one of the few public schools to adopt the recommendations of the Fleming Committeein 1944, which attempted to bridge the gap between the state and the private sectors, offering places to Middlesex grammar school pupils.

One of the book’s strengths is the sophisticated exploration of the relationship between the school on the hill and the community that surrounds it. The healthy air was an early selling point - travel to London was made much easier by the coming of the railways and the Metropolitan line. The governors bought land around the school, which prevented urban sprawl.

In the final chapter, the remarketing and repackaging of Harrow in the 1990s by Ian Beer, the first headmaster to be both a rugby international and holder of a science degree, is illuminating. In spite of, or perhaps because of, changes in state schooling since the Second World War, the school has continued to attract pupils.

Its influence at all levels of public life, graphically depicted in 1924, when the prime minister, Stanley Baldwin, and a third of the Cabinet as well as the Archbishop of Canterbury, were all Old Harrovians, suggests one reason for its continuing success.

Tyerman has written a stylish and elegant account, told with insight and clarity. The book, which is not likely to be superseded, would be of interest to many teachers.

Peter Gordon is emeritus professor of education at the London Institute of Education, University of London