Margaret Thatcher left many legacies, but one of the most enduring was the radical change to the English education system - it was her most significant social reform.

Jim Callaghan, then Labour prime minister, had kicked off a great debate on the curriculum in his Ruskin speech in the 1970s (at a ceremony laying the foundation stone of the extension of Ruskin College, Oxford in 1976), but very little was done about it by subsequent secretaries of state, including Shirley Williams, Mark Carlisle and even Keith Joseph.

Joseph was interested in curriculum matters and did set up various committees to try to move towards a national curriculum (it’s easy to forget that we didn’t have one until the late 1980s), but being a conceptual thinker he was rather seduced into very arcane debates with senior officials, and so little was actually implemented during his time in office.

Appointed to the role of education secretary in January 1986, I went to see Margaret, expecting to be given a list of what she wanted done. In fact, she asked me to go away and think about the necessary reforms for the school system and come back to her in eight weeks with my proposals. This rather counters the belief that Margaret dominated her ministers and told them what to do - indeed, that was not my experience.

My officials and I favoured a broad-based curriculum, similar to the one eventually introduced. Margaret did tell me that she wanted the basic subjects of English, maths and science to be given priority.

Along with the national curriculum came testing and league tables, and Margaret was very enthusiastic about my proposal to establish technical schools independent of local authorities. She was no great lover of education authorities for she held them responsible for the inadequacy of the school system.

Liking the idea of state-funded independent schools, she asked if this could be broadened out: this was to lead to grant-maintained schools. She at no time asked me to create more grammar schools and although she liked the concept of the old direct grant schools, where some parents contributed some of the cost of their children’s education, she never asked me to reintroduce these, which would have been explosive.

We both wanted a much wider choice of schools with as much variety as possible - single-sex, religious, grant-maintained and city technology colleges; parental choice was established as a key issue very early on.

Although these issues were radical, they avoided the explosive issues of selection and charging. There was absolutely no desire to open up a battlefront in these areas when one of the tasks I had was to resolve the teachers’ strike, which by that time had been going on for two years.

Going down in history

After the election in 1987, Margaret chaired the committee drafting the bill that would eventually become the Education Reform Act 1988. We did not always see eye to eye. On one occasion, I simply got up and walked out. Compromises were made, and in any case as time went on the vigour of debate was much reduced and I was able to get through most of what we wanted.

I knew that the new history curriculum was going to be controversial. Being a historian myself I very much wanted a linear structure around the main elements of British history. That certainly chimed with Margaret’s view. However, the initial draft downgraded knowledge and favoured the examination of sources and a very wide, fragmentary range of subjects. We got that changed later.

It is wrong to say that Margaret could bully her own changes through. She liked a fight. She was always very well briefed and her marks often extended to the last page of a document. If she felt she was on the retreat she used her ultimate weapon - the handbag. She would take out of it a scrap of paper from someone in her private network of advisers and informants, which meant she had received an anonymous briefing. She would then say what she had just heard about the failure of schools in, say, Croydon and what was I personally doing about it: all of which she had heard from her hairdresser earlier that morning.

When it came to the other issues such as city technical colleges and grant-maintained schools, Margaret was very supportive. I really did need her support in this respect because many Conservative MPs did not approve of grant-maintained schools and there was quite a coordinated movement to erect impossible hurdles of consent for the electoral process, which would have stopped them in their tracks. Margaret would have none of this and backed me very strongly, which is what a great leader does, instructing her chief whip to check the revolt and get the bill through.

At the time, the Labour Party was opposed to many of the changes - particularly testing, league tables, city technical colleges and grant-maintained schools. But when they came to power in 1997, David Blunkett and Tony Blair, advised by Andrew Adonis, decided to keep every aspect of the act apart from grant-maintained schools. In Labour’s third term, however, even these were resurrected as trust schools; and then academies appeared. The vast majority of our reforms have endured because eventually a cross-party consensus emerged. We won the argument and change became irreversible.

Lord Baker of Dorking is co-founder and chairman of the Baker Dearing Educational Trust.