When Chris David arrived as head of Oakdale comprehensive, the school was in trouble. Results were low, pupil numbers were falling and the staff had "given up".
But in just three years Mr David has transformed the school's fortunes, with record numbers of pupils achieving good GCSE results and its teaching quality named among the best in Caerphilly.
As school performance in Wales comes under intense scrutiny following poor results in last month's Pisa (programme for international student assessment) survey, Mr David is calling for teachers to be given more power.
Schools will not improve unless they invest in their teachers, treat them like professionals and allow them to take risks, Mr David told TES Cymru.
"When I came here in 2007, I could see the staff had given up," he said. "They were going through the motions and crying out for leadership. I knew they just wanted someone to believe in them. So I said, `Let's set our stall out and aim to be number one.' And that is what we did."
Since then results at Oakdale, in Blackwood, have improved dramatically, with the proportion of pupils achieving five A*-C GCSEs up 30 percentage points to 71 per cent. Such a radical improvement could not have been made without the "fantastic" teaching staff, according to Mr David.
"It's all about giving staff confidence and self-belief," he said. "Allowing them to try different things has taken them out of their comfort zone and stretched them, enabling them to perform at a very high level. We have tried to be innovative every time we have done something."
When Mr David arrived at Oakdale, the 11-16 school had seen three heads in quick succession and, according to teachers, it had become "stagnant".
The school was facing an Estyn inspection in November 2008, so Mr David launched a review, closing for a day to give staff the chance to conduct an honest appraisal of its good and bad points.
As part of a wider reorganisation, one senior teacher was made head of teaching and learning, and five others became designated co-ordinators for raising standards.
BTEC courses were added to the curriculum and the school invested pound;50,000 in a catering suite and pound;34,000 in a media room. Oakdale also found money to invest in new classroom equipment, uniforms for admin staff and CPD training for teachers.
Schools may find making similar investments more difficult as budgets are squeezed but, money aside, staff have praised the change in Oakdale's atmosphere and ethos.
Stuart McNeil, technology curriculum leader, said: "The head has really driven staff. He's always willing to take risks and do new initiatives and that has rubbed off on us."
Assistant head Matthew Thomas said: "It's been a dramatic change. We have excellent staff here that work extremely hard. It's a very happy place to work."
Another of Mr David's changes was to introduce regular morning briefing sessions with all his staff, giving them an open forum to share information.
"I tell my staff everything - budget issues, problems with pupils, issues with the local authority. I'm very open," he said. "I trust them with information that other heads wouldn't. But by doing that I get more back from them."
- Original headline: Empower staff to achieve turnaround, says top head