Just over a decade ago, families were leaving Inner London in their droves to avoid local schools. The education system in the capital was lagging behind the rest of the country, with lower pass rates at GCSE and large gaps between different socio-economic groups. As a result, schools faced a real struggle to attract quality teachers and parents were voting with their feet.
But there has been a turnaround. The capital now leads the pack, as last week's TESS ("The London wonderground", 27 June) pointed out. The city's students, including those on free school meals, outperform the national average.
What has brought about this transformation? London's teaching landscape has certain natural advantages: a wealthier population, greater resources and a growing number of motivated immigrant families. But these factors have always existed and ethnic diversity was previously seen as a hindrance.
A recent flurry of academic and thinktank studies have pointed to the significance of the Labour government's initiatives in the 2000s, most notably the London Challenge. The scheme, established in 2003, paired successful headteachers with those in less well-performing schools. In doing so, it nurtured a strong network of professional support, as well as a sense of shared identity and mission. By opening up schools to new influences and encouraging great leaders to mentor others, the London Challenge fostered a spirit of collaboration.
Interestingly, although the scheme evokes misty-eyed nostalgia in today's school leaders, who dislike the current government's emphasis on top-down structural change and competition, it is worth remembering how much initial resistance this pan-London initiative faced. Many boroughs felt the government was encroaching on territory best tended by local politicians, no matter how poor the results.
And although collaboration was clearly important, the government at the time was far from averse to competition. Recognising the need to kick up the dust, it encouraged new entry into the system. Academies introduced a different type of school governance, free from local authority control, which transformed expectations about what a comprehensive could achieve. Mossbourne Community Academy, opened in 2004 on the site of the old Hackney Downs School (once dubbed "the worst school in Britain"), typified this approach. Within a few years, this new type of school was getting children from the poorest wards in the country into Oxbridge.
In both cases - the London Challenge and academisation - there was a strong impetus to do better and to do differently. Poverty was no longer an excuse. Consequently, London has become a national test bed for ideas. The Teach First scheme, launched in the city in 2002, was set up to address the poor supply of good teachers by offering a new training route into the profession. More recently, the highest number of new free-school applications have been made in London - many of them by Teach First graduates.
None of this is to underplay the serious challenges still facing the capital's schools. Approximately one in five children are functionally illiterate when they leave primary. At the other end of the scale, more-able students at later key stages need to be stretched academically to help them get into the best universities. Nor have London schools been immune to wider, corrupting trends in education - the introduction of new GCSE vocational "equivalents" in the mid-2000s, for example, which incentivised schools to push these easier subjects to enhance their league table results.
Yet the calibre of the teaching profession in London and its sense of collective identity mean the capital is arguably the region best equipped to find solutions to these problems. Teachers are motivated to improve the system because they are buoyed by their previous experience of change. Success begets success.
London is also governed by a mayoral system that can capitalise on this can-do attitude. In 2012, the mayor launched a pound;24 million London Schools Excellence Fund to support teacher-training partnerships between state and independent schools, universities and charities, to increase specialist teacher knowledge in a range of subjects. Like the London Challenge, it seeks to harness expertise in the system, this time at a classroom level.
In addition, a new Gold Club scheme recognises the top strata of London schools that are achieving exceptionally good results for their students, especially those from disadvantaged backgrounds. In its first year, more than 100 schools have won this accolade and committed to sharing their good practice.
And we must not overlook the rich learning resources afforded by London itself, with its unparalleled range of museums, galleries, theatres, universities, science institutions and architectural and heritage sites. A new London curriculum, designed to complement England's new national curriculum, is being piloted in secondary schools and could unleash excitement about learning in a way that inspires teachers and students alike.
Ultimately, what most impresses about London is the resolve of its teachers to keep getting better. Long before the 2012 Olympic Games, the city's schools were on a collective mission to beat their personal bests. Although they still face challenges, they do so with faith in their agency. It is this that explains the miracle of London.
Munira Mirza is London's deputy mayor for education and culture