Oxfam volunteers celebrated the 21st birthday of the charity’s book shop in St Giles — and raising £4.1m in the past two decades for the poor and hungry abroad.

On Friday, Colin Dexter, Philip Pullman, Mark Davies and Sophie Grigson appeared at a sold-out event at the nearby Friend’s Meeting House.

And on Saturday, Oxford’s Lord Mayor Susanna Pressel was joined by author Sir John Mortimer and Oxfam volunteers to cut a cake at the shop.

Manager Nihal Alahendra, 44, thanked volunteers for helping to organise the anniversary event and local authors for donating signed copies of their books to mark the occasion.

He said: “This anniversary is an exciting time for the shop and its volunteers and I see this as the beginning of great things to come.

“Volunteers have helped to raise £4.1m over the past 21 years, which is an astonishing amount. That money can make a real difference to the lives of those in need.

“We would like to thank local authors who have dropped in with signed copies of their books and local businesses who have supported the anniversary event.”

Ms Pressel said: “Raising £4.1m is an amazing achievement — I congratulate the volunteers and I’m sure they will go on to raise millions more.”

The St Giles shop was the first specialist Oxfam book shop in the country. There are now about 130 nationwide.

The Oxford store is the third most profitable, behind only Glasgow and Marylebone in London, and last year’s turnover was £290,000.

Earlier this year, volunteer Andrew Chapman picked out a donation, an early Graham Greene novel, Rumour at Nightfall, and thought it might be worth a lot of money.

The first edition of the 1931 novel was given a guide price of £6,000 to £8,000 — but eventually sold at auction in March for £15,000.

An Oxfam trade fair featuring Fairtrade stalls was also held at Oxford Town Hall in St Aldate’s on Saturday.