An early encounter with the British Council might have put David Green off applying for the top job.

He recalls his time as an 18-year-old volunteer in a secondary school in Pakistan with Voluntary Service Overseas - an organisation he was later to run. During a school holiday, he and a friend went to Afghanistan and agreed to bring a car back for a British Council man who had left it in Kabul. However, when they reached the border post at the top of the Khyber Pass, the guard demanded to see the log book and paperwork. Neither was in the car. Mr Green was arrested and his companion had until 10am next day to make the seven-hour bus journey to Islamabad and bring back the documents. He just made it, along with an embarrassed British Council official. “I had a pretty uncomfortable night in a cell,” said the new director-general. But obviously no hard feelings.

Next Monday Mr Green will be the first former teacher to take charge of the British Council, which operates in 110 countries promoting a wider knowledge of the UK and the English language. It is a huge organisation, with a pound;424 million turnover and nearly 7,000 staff worldwide.

But Mr Green, a genial, bearded man, seems undaunted. After all, he has directed VSO since 1990, turning it into the world’s biggest independent volunteer agency, with a pound;27.5m budget, 500 staff and 2,000 volunteers working in 60 countries. “Once an organisation gets to a certain size you can only work through a similar structure,” he says. “I had eight people on the senior team at VSO, the same as the council. The same goes with the statistics - apart from the odd nought.”

Despite that first encounter, he has worked closely with the council, making a point of contacting representatives in each of the 50 or so countries he visited during his VSO days. At least 10 country directors are ex-VSO volunteers and as for headquarters: “The place is riddled with them. I feel I’m returning to friends.”

He intends to spend the first six months “listening madly and seeing how things work. The staff are a talented group who have taken a bit of a knock. They’ve had a tough 18 months and need some stability.” This is a reference to the sudden departure of the previous director, the scientist Dr David Drewry, whose resignation late last year after only 10 months in post caused some raised eyebrows and set off rumours of disagreements with the new chair, Helena Kennedy QC. “She’s a strong-minded person and I’m looking forward to working with her,” says Mr Green.

“I want to ensure that we’re projecting an up-to-date Britain, not corgies and Beefeaters but modern Britain, warts and all,” adding that it worried him how little known the council was at home. “Former governor of Hong Kong Chris Patten said something like ‘the council is the best British institution that no one’s heard of’.”

He is keen to capitalise on the demand for English language teaching at which the council excels - it employs 1,700 teachers of English as a foreign language. “There’s huge scope to extend this work with our high quality teaching.”

Mr Green’s volunteering experience changed his life. Instead of taking up a place to study architecture at York University, he enrolled on a teacher training course at Keswick Hall College, Norwich, followed by a B Ed at Trinity Hall, Cambridge.

After five years teaching art in two South Yorkshire comprehensives in the early 1970s, combined with a year as a tutor, he became a bit disillusioned. “I was very idealistic.” And he feared he would get stuck. He decided to get out of education for a while.

Pakistan beckoned. A headteacher he’d worked with invited him to produce an opera in Karachi. He directed 200 children in All the King’s Men by Richard Rodney Bennett, designed and built the set and trained the band.

On his return he directed Children’s Relief International, a Cambridge-based charity running camps for disadvantaged children from Liverpool, Leeds and Birmingham with Cambridge students; schemes for young offenders; and community projects for Vietnamese boat people. He negotiated a merger with Save the Children, rising to deputy director under the leadership of the late Nicholas Hinton, before taking over VSO in 1990.

A close colleague said he created a positive working environment with a “gentle and thoughtful style”. There was a lot of onus on staff to resolve their own problems as he would only intervene when something was going astray. “At its worst it appeared he was sitting on the fence for too long; but in most cases the problem got resolved. There were few bad decisions, but it could be frustrating. It was an empowering style of management, one which depended on the goodwill and ability of the next level down; but David proved adept at choosing his directors.”

Mr Green has kept his interest in art, taking his sketchbook wherever he goes, catching the early light before meetings or whiling away the time waiting for planes. A friend recalls a painting of a local airstrip - a beach on a remote island in the Solomon chain- he’d sent to a volunteer lawyer as a thank you; and a photograph of him surrounded by soldiers in Cambodia as he serenely sketched the Ankor Wat.

Although he’s a product of a public school, The Leys in Cambridge, his three teenage daughters are being educated at separate comprehensives in south London, where he lives.

Does he regret giving up teaching? “I’ve often thought I’d like to go back to mainstream education. Half-way through my career in Save the Children I thought of running a school, but other things came along that were too interesting to give up.”