John Armstrong, a past pupil and teacher, has introduced a raft of changes since taking control of the school in 2006. He was awarded the Royal Air Force Award for Headteacher of the Year in a Secondary School in Northern Ireland - which applies to all post-primary schools - at a ceremony in the Waterfront, Belfast on Monday. The gong was presented by the Teaching Awards organisation, which recognises achievements in the field across the UK.

Mr Armstrong was credited as the driving force behind many of the changes at the 500-pupil school.

Speaking to the Times, Mr Armstrong said that he accepted the award on behalf of staff, pupils, parents and governors. Nominated by a pupil, the identity of whom Mr Armstrong has yet to discover, and a little surprised by the outcome, he said: "I'm thrilled and I'm honoured for myself and the school and for Larne. I feel this is an honour for the town. This is a great finale to our 50th anniversary year."

Pupil intake is up this year, he said, to 108 and the school's reputation continues to grow. The Larne man, who said he did not know about the nomination until late in the process, and other regional winners will attend a national finale at the London Palladium in October.

According to the judging panel, the school has been "transformed into one of the most popular secondaries in the area. In the space of barely a year, results have risen by a third, exclusions have gone down and pupils have a renewed sense of pride and achievement in their school."

The pupil who nominated Mr Armstrong said: "He has made a remarkable change and there is no other principal in the UK that could achieve what he has done. His inspiration is motivating for the pupils and teachers."

Vice principal John Nicholl praised Mr Armstrong's people skills, saying: "I have been present on a number of occasions when parents have arrived in a very aggressive manner and left calm and fully supportive of the school's stance."

Mr Armstrong, the judging panel said, can be justifiably proud of his achievements and his "vision to raise standards to such an extent that parents in the area will consider the school as their best option."

The panel also noted the principal's care for the school and the community. One noted: "Everyone we met testified both to the clarity and simplicity of his vision for the school and to its power, not to mention John's capacity for articulating it and securing the enthusiastic support of others."

John is married to Olivia, who is the head of English. He paid tribute to the support she has given him all through his career.

The Teaching Awards, an annual celebration of teaching and learning, were established by Lord Puttnam CBE in 1998 with a guiding principle to recognise excellence within the profession.

The final event to mark Larne High's 50th anniversary celebrations will be a short service in First Larne Presbyterian Church on Tuesday, June 24 at 2.00pm.