Bishop's Hatfield girls' school in Hatfield, Hertfordshire, was only kept open in the mid-1980s through the campaigning of staff, governors and parents, after falling rolls threatened its future.
But now the school, which has beacon status, is thriving. This week it was celebrating because its A-level results made it the sixth best comprehensive in the country, when ranked by average grade per exam entry.
The achievement is all the more creditable as three out of the five above it in the tables are partially selective. Its score of 94.4 points meanst that the average A-level and AS grade at the school is just below a B.
Head Christine Brooks put the school's success down to good teaching, and its emphasis on pupils taking responsibility for their own learning.
The school council was given pound;5,000 a year to spend on projects of its own choosing, and "active citizenship" has been a major part of the Bishop's Hatfield's ethos.
Mrs Brooks added: "We are all delighted. We thought the results in the league tables would be good, but we didn't know they were quite this good.
Hasmoneon high school, a secondary in Barnet, north London, for children from Orthodox Jewish families, was the top performer among schools with fully comprehensive intakes.
Rabbi David Radomski, headteacher, said the result was especially remarkable as much of the school day at Hasmonean is taken up by religious study.
Hasmonean also came third nationally among schools ranked for "value-added" between key stage 3 and GCSE.
Rabbi Radomsky put the results down to "exceptional teaching and very ambitious pupils and parents.
"Pupils, staff, parents and governors have very very very high expectations," he said.
Independent schools dominated the overall A-level rankings, filling the top 43 places, again listed according to the average grade per entry. Top was the North London Collegiate.
Hills Road college in Cambridge was the top-performing sixth-form college.
Schools are also ranked according to the average number of university entry points achieved per student.
On this measure, Greenhead sixth-form college in Huddersfield came out on top among state schools and colleges. Its score of 412.3 equates to an average of two As at A-level and an A and a B at AS, putting it well clear of the others at the top of the table.
In second place was King Edward VI college, Stourbridge, west midlands.
Welbeck college, in Worksop, Nottinghamshire, was third.