Five years ago, the Rutli Hauptschule became Germany’s most notorious school after teachers published a letter saying conditions were so bad it should be closed down.

Dominated by Arab and Turkish youths and located in Berlin’s heavily migrant-populated Neukolln district, Rutli became a byword for the nation’s failure to integrate such youngsters into its education system.

At the time, police were brought in, riots escalated and violence erupted. The media got caught up in the frenzy, enticing pupils to throw waste-paper bins out of classroom windows and snapping pictures of a school descending into utter chaos.

The ensuing headlines sparked fierce debate across Germany’s political spectrum and throughout the educational establishment. At the heart of the discussion was the future of the Hauptschule, the lowest rung on Germany’s three-tier secondary ladder and a school type that had come to stand for failed integration.

Since then, however, Rutli has changed beyond recognition and its future looks rosier than anyone ever dared hope. This is owing largely to a charismatic new headteacher, Cordula Heckmann, who has been at the helm since 2009, working tirelessly to reverse the school’s fortunes.

And her efforts haven’t been in vain. “I try not to complain about what I don’t have,” she muses. “I just accept the resources we get and make the best of it.”

This includes winning over teachers to work at the school, including those with migrant backgrounds, attending workshops and seminars, and reading emails in her spare time so school hours are free for pupils and colleagues.

Under her leadership, the school’s reputation has steadily improved and a third of last year’s intake will continue up to Abitur, Germany’s higher school-leaving certificate. These are phenomenal achievements for Rutli, once the nation’s most shunned educational establishment and now known as Neukolln’s number one comprehensive since merging with a nearby secondary modern and primary school.

Thanks to the merger, Rutli pupils now number a robust 600-plus. This year, the number of new applicants doubled compared with last year - a triumph for Ms Heckmann and her team. Of these, about 90 per cent have migrant backgrounds or are too poor to buy their own school books, so there’s plenty of work ahead. Despite this, the head has achieved the seemingly impossible and put the school back on track. Incredibly, she still finds time to teach: English, German and ethics.

The school is also closely linked to nearby Campus Rutli, a community project incorporating a kindergarten, sports and leisure complexes, youth clubs and a job advisory centre. While the Berlin state government is the chief investor, project leader Klaus Lehnert successfully campaigned for extra funds from business sponsors and private foundations.

With the local multi-ethnic community firmly behind the project, he is optimistic about the future. “There’s a positive feeling among teachers, parents and residents,” he says. “We’re pulling together to make it work.”