Success: not just for clever clogs;Case study;School League Tables;Results analysis
In many ways, very little has changed. Forty-two per cent of the Church of England girls' school's pupils are entitled to free school meals and headteacher Elizabeth Phillips' annual budget for each child is close to a term's fees at her private rivals.
And yet it will be St Marylebone and not its neighbours, Francis Holland school and Queen's College school, that will be receiving plaudits this week.
The school's results are among the most improved in the country over the past three years, with 77 per cent of pupils securing five A* to C grades this year compared to 41 per cent in 1996. No pupils left St Marylebone in 1999 without a GCSE, compared to 8 per cent three years ago.
The two private schools still comfortably out-perform their state school neighbour (in both, more than 9 in 10 students get five A* to Cs) but their results are static. The poor neighbour is catching up fast.
Mrs Phillips is quite explicit about her intentions: "I have set out to see how near an independent education you can get with state education. These are the kids that need the time, the money, the assets, all the things they haven't got in some of their estates."
The obstacles to progress have been complex. As well as its relative poverty and the effect of private and selective schools creaming off its intake, St Marylebone contains 35 nationalities and nearly 60 per cent of its pupils speak English as an additional language.
Yet it now attracts about six applications for each of its places. A previously highly-mobile school population has stabilised as families seek to hold onto prized places.
Mrs Phillips says the improvements at the school have been gradual: "You can't turn a school round straight way, whatever Chris Woodhead says. You can make some refinements and improvements - you can set down good discipline and good order - but it takes time for that to work through."
This year's high achievers joined the school after Mrs Phillips became head in 1992 and, she says, have benefited from their single-sex environment, a regime of "finickity" discipline, ability setting and relentlessly good teaching ("If you have one bad lesson, it undermines the ethos in all the rest").
The school has been recognised as a specialist arts college, runs a state-of-the-art recording studio and funds thriving drama and music departments from grants and private sponsorship.
But it is St Marylebone's comprehensive ethos which Mrs Phillips believes sets it apart from its neighbours. Despite its popularity, her school regulates its intake to make sure it takes as many low-ability children as high-flyers.
"I don't mind if I go lower down the league tables if I am entering those for whom an E grade might be the biggest challenge. Anybody can get the clever clogs through. It is getting the others to improve that is difficult. That is the challenge that the independents don't have.
"There was a girl who we didn't think would get anything last year and she got five A to Cs. You should have heard the whooping in the office. That is what we are all about."