Actress Jane Asher joined pupils and staff at the National Autistic Society's (NAS) Radlett Lodge School to celebrate their 40th anniversary on Friday.

Mrs Asher, who has starred in the BBC drama Waterloo Road, is also the NAS president.

She attended individual parties held in different classes, before joining the whole school for a balloon launch in the afternoon. Over 50 balloons were released - one for each pupil at the school.

Radlett Lodge School is an independent residential special school that opened in 1974. At the time it was the third NAS school.

Today, the school supports 55 pupils with autism, aged four to 19 and runs a residential service for 14 pupils on either a weekly or termly basis.

Mrs Asher said: "Over the many years I've been involved with the NAS, one of the things I have always been most proud of is our pioneering work in the field of education and support, and Radlett Lodge is a prime example of what has been achieved.

"At a time when many children with autism were still being denied any suitable provision for their condition and little was understood about the importance of early intervention, the school began its remarkable work, and it's extraordinary to think that forty years have passed since it first opened its doors.

"I feel so honoured and delighted to have been included in the celebrations of this significant anniversary.

"Radlett Lodge is a model of the kind of provision that every child with autism deserves."

Headteacher of the school, Jo Galloway said: "We're so proud to reach this anniversary and are delighted that Jane could be there to celebrate with us.

"Our success over the past 40 years is a testament to our staff's commitment to ensuring that the children and young people in our care have the best education, the best opportunities and the best start in life.

"Autism is a serious and lifelong condition but we've seen how the right support can help every child to fulfil their potential and we look forward to helping more pupils in the years to come."