Justine Greening, dismissed earlier this month, was the ninth female education secretary - very easily the most popular berth for female Cabinet ministers throughout political history.

Three times more women, indeed, have served in this capacity than in any other senior position in government. Three women have been home secretary (Jacqui Smith, Theresa May and Amber Rudd), the same number as health secretaries (Barbara Castle, Virginia Bottomley and Patricia Hewitt). In contrast, two women have been prime minister, while Margaret Beckett has been the sole female foreign secretary, and none has served as defence secretary.

Some formidably talented woman have served as education secretary. Yet, very surprisingly, only one - Labour’s Shirley Williams - has made an enduring mark. All the other eight experienced varying degrees of difficulty, and very few sparkled. The question is why? My supposition is that this has a lot to do with luck, and a fair amount to do with sexism. But first, let’s have a canter through political history.

Setting a precedent

Ellen Wilkinson (1945-47) was only the second woman to be appointed to cabinet, after Margaret Bondfield, labour secretary in the Labour government of 1929-31. There were very high hopes for her. But after 1945, she showed little of her former flair or radicalism with education. Raising the school leaving age from 14 to 15 was her major achievement. She died in early 1947 from an overdose of medication; her anxiety that she was about to be replaced in a reshuffle fuelled suspicions that she had taken her own life, a case that is unproved.

The precedent of a female education secretary had been established and Winston Churchill appointed the redoubtable Florence Horsbrugh (1951-54) when he returned to power in October 1951, only to find her far too strait-laced for his taste.

Indeed, when he realised that he had somehow appointed her on the nod in a Champagne-fuelled cabinet formation, he tried to replace her until his aides protested that he simply could not. The lacklustre performance of these first two education secretaries might be explained away by neither being big-hitting front-ranked politicians. That could not be said about the next figure to pick up the poisoned chalice.

Ted Heath was far from enthusiastic about appointing Margaret Thatcher (1970-74) to education in June 1970. She was formidably capable in post, of course, and ran a tight ship. But in contrast to her decisiveness and strong lead as prime minister, she was unremarkable in this post, best remembered for the adage “Thatcher, Thatcher, milk snatcher” after scrapping free school milk, a move described by her opposite number on the Labour benches as “the meanest and most unworthy thing” he had seen in 20 years.

‘Heavily skimmed’

Shirley Williams (1976-79) was of a different stamp, the daughter of social reformer and writer Vera Brittain. She’d already been in senior positions in several departments including at the home office and the Department for Education before being appointed education secretary. A charismatic and popular figure, she drove forward the comprehensivisation of schools against staunch opposition.

She later said that she regarded the spread of comprehensive schools as her greatest achievement and that she never regretted getting rid of grammar schools because they were “heavily skimmed”. Barely remembered today is Gillian Shephard (1995-97), John Major’s education secretary: supremely efficient, but not an innovator nor a game-changer.

Estelle Morris (2001-02) was perhaps the most popular female education secretary across the board. In many ways she was ideally suited to the job, not least because of her experience as a primary school teacher and educational researcher. Self-doubt about her management ability, however, soon got the better of her. Many were disappointed when she fell on her sword, declaring that “I have been as effective as I should be or as effective as you need me to be”.

Ruth Kelly (2004-06) had many of the qualities needed to have been a superb education secretary and became, at 36, the youngest woman ever to sit in the cabinet. Her period in office was dogged by controversy over sex offenders, clashes with fathers’ rights groups and the influence of her strongly held religious views. After a string of controversies, she was moved out of the post in May 2006.

Insufficient time in office militated against the two most recent education secretaries making an enduring mark. Nicky Morgan (2014-16) showed verve and leadership, particularly on character education and teaching resilience, but fell victim on Theresa May’s succession to prime minister.

One of the unluckiest incumbents of all in the ministry has been Justine Greening (2016-18), who was made uncomfortable from the very outset by Number 10 driving an agenda that was not her own. She had a deep, personal commitment to boosting social mobility among the disadvantaged. But her relative popularity with the profession may even have proved a disadvantage for her. Knocked from pillar to post by Number 10, she left the department that she might with more time have shaped to her own convictions.

Patronised by men

So why have women not made more of an impression? To be clear, most men have not often fared much better, though several are identified with significant innovation, including RA Butler (1944-45) with the 1944 act; Anthony Crosland (1965-67) with the end of the tripartite system; Ken Baker (1986-89) with the national curriculum; and Michael Gove (2010-14) with his demands for an “academic education for all” and his promotion of the academy programme devised by Andrew Adonis, the most influential politician in the field never to have been education secretary.

Brevity in office perhaps best explains the failure of more female education secretaries to leave a more enduring legacy. The average length of their service has been just two years, which is plainly not enough to shift the dial permanently. But one can be sure that sexism across the profession and across Whitehall has played a part. Female incumbents have been patronised - by unions, local authorities and policymakers at the centre.

Perhaps men have found it easier to launch big initiatives, whereas the women in office have been expected by their political masters to be more willing to toe the line and/or sit quietly. Many women have excelled at managing education, but this arouses less public attention than eye-catching changes. Men, too, will have found it easier to stand up to Number 10 when it has tried to run education policy.

Morris, Kelly and Greening were all under the cosh. Perhaps the boys’ clubs that too often manifest themselves in Downing Street unconsciously felt more comfortable keeping them in their place - and then accepting their departures - because they were women.

To make a successful education secretary, the incumbent needs charisma, self-belief, stubbornness and passion in abundance. Many of the female education secretaries have had all these qualities, but you also need a collaborative or weak Number 10. Few had that luck.

Being education secretary is possibly the hardest job in Cabinet, with an extraordinarily tough job balancing political forces in Whitehall and a series of almost insoluble difficulties in the in-tray. But pick the right women in the future and there’s no reason why they can’t outperform men, as they have in so many other spheres.

Sir Anthony Seldon is vice-chancellor of the University of Buckingham, and a former master of Wellington School