A school is celebrating after winning a prestigious national award.

St Helen and St Katharine's in Abingdon has been named as the Sunday Times Independent School of the Year.

It has risen from 62nd place last year to 17th in the league tables thanks to the impressive exam results: 85.6 per cent gaining A* and A grades at GCSE, up from 70.5 per cent last year and 81.7 per cent gaining As and Bs at A-level, compared with 71.8 per cent.

St Helen and St Katharine's also finishes among the top dozen day schools for value for money, with its fees of 1,979 a term.

It is a small, rural school compared with nearby Radley College and Oxford High School for Girls, and has a catchment area of 25 miles. Cynthia Hall, headmistress, came to the school in 1993 and was previously head of English at St Paul's School for Girls, which regularly tops the results league tables.

An inspection report in March by the Independent Schools' Inspectorate praised St Helen and St Katharine's academic record, its strong sense of community, relationships in the school and the generous staff levels.

Mrs Hall said: "We are absolutely delighted. Quite often it is the same schools at the top of the league, but they have picked us out as a school that is not always at the top and not everybody knows about nationally.

"It is a combination of keeping the Cs at a reasonable level and relationships in the school which they found to be good.

"As far as staying at the top of the league tables goes, I think to be in the top 20 every year, we would have to use certain techniques. Some schools won't let girls do a subject in the sixth form if they won't get an A and we are not prepared to do that. That is not education."

St Helen's was founded by Anglican nuns in 1903 to provide a Christian education for girls in the area. In 1938 it was joined by St Katharine's School in Wantage.

Mrs Hall's predecessor, Yolande Paterson, whom she credits with improving the school's overall reputation, developed a healthy academic record over 20 years.

Last week, the former head returned to open a 1.5m English and modern languages wing a symbol of the school's confidence and success.

Fundraising is continuing for two more buildings a performing arts centre and a library.

One third of the subjects at sixth form are taught with boys at Abingdon School and the schools regularly collaborate in drama productions and share foreign exchanges.