I was saddened to hear of the death of Chris Woodhead after his long struggle with motor neurone disease and, later, cancer. For a man who once exercised such influence over education and excelled as a rock climber, recent years must have been a terrible struggle. The last time he and I exchanged notes he said how hard it was to see the North Wales mountains around him and know he would never again walk their summits.
I had the pleasure - and challenge - of working very closely with Chris through much of the 1990s. We had built a rapport in the early part of the decade during his time as chief executive of the National Curriculum Council (NCC) quango, where I represented the NUT teaching union as head of education.
My favourite "Deep Throat" moment was when Chris arranged for a copy of a suppressed NCC report on national curriculum English to be passed to me in an underground car park.
In 1994, Chris was appointed head of Ofsted under the Conservative government of the day and soon caused outrage with his attacks on incompetent teachers and failing schools. It is often said that Chris could have been more emollient but it is hard to see how this would have worked. It was his willingness to spell out what he thought in plain, uncompromising language that changed the nature of the debate. This was his historic role. Meanwhile, the defensive reaction of many teacher leaders simply played into his hands. There were, in any case, many headteachers who silently applauded all that he did.
When Tony Blair became prime minister in 1997, I joined David Blunkett, the incoming education secretary, to work on ensuring the implementation of the school standards agenda. The minister also gave me responsibility for managing relations with Chris and Ofsted, which we knew would be difficult. There is always an institutional tension between the Department for Education and the regulator - indeed, there should be.
At that time, Chris's reputation and personality added extra spice. There had never been any doubt that Mr Blair wanted to keep Chris in post, simply because New Labour agreed with the basic case he made.
I talked with Chris regularly in my new role, often over dinner in Covent Garden at places such as Joe Allen's - he never swayed in his trenchant advocacy of his beliefs.
Sometimes our debates were in more exalted locations. We were once guests at Chequers, where Mr Blunkett asked me to make sure I involved myself in conversations between Chris and the PM. Chris and I tried (but failed) to persuade Mr Blair that the literal implementation of his pledge to cut class sizes would be a mistake. Another time, we were both guests of Prince Charles - a fervent admirer of Chris's - at Highgrove, along with Mr Blunkett and others.
Holding councils to account
Chris and I both thought phonics should be central to the teaching of reading. We also agreed that local authorities should be held to account for turning around failing schools and, in 1998, legislation was passed that allowed central government to intervene. Chris challenged us to act and I suspect he was expecting us to flinch. But we had always intended to act.
To allow us to do so, however, we needed incontrovertible evidence - and this was where inspectors were key. Our challenge to Chris, which he accepted, was that too often Ofsted's reports took refuge in waffle.
Interventions in places such as Islington, Liverpool and Leeds were controversial, but later evidence suggests they made a real difference. Chris believed the success was Ofsted's responsibility. The truth was that it also required Mr Blunkett's fierce political will and effective implementation.
Around this time, we had regular stock-take meetings in No 10 with the DfE ministerial team, Chris and the prime minister. For these meetings, Chris and I would produce a joint paper, with the text often a matter of vigorous negotiation.
Once at the end of a challenging call with Chris, I swore - my staff wished I had put the phone down before doing so!
However, at times of tension such as these, we could always fall back on our shared love, which transcended everything, of the mountains of the Lake District and North Wales.
And now our debates can be judged historically. He thought we had too many initiatives and that Education Action Zones were a mistake; he was right. He was no fan of the Excellence in Cities programme, which led to the London Challenge, but these worked. Ultimately, Chris was suspicious of government whereas I thought it had a role - as indeed his own work proved.
I welcomed his independent and critical reports on government programmes, which meant that I shared with headteachers the risk of being bashed by Ofsted. My regret was that the reports were often out of date by the time they emerged.
The schools system improved significantly during those years and the need to challenge poor performance is now accepted. Millions of children and young people have benefited.
Chris relished controversy and was not always easy to work with, but he was a huge figure in English educational history, the biggest single influence on improving education in England in the 1990s. By making standards central, he set the agenda for two decades.
Sir Michael Barber was chief adviser on school standards to the Labour government from 1997-2001 and is author of How to Run a Government