The Englishman's dream of his own castle has come true for an Oxfordshire millionaire.

The 18th century 'folly' that Ian Richens has bought is a former National Trust property, which once housed a garrison of 250 men and 32 cannon.

The castle - Rodborough Fort, on top of a hill overlooking the town of Stroud in Gloucestershire - cost him and his wife Maeve almost £2m and still needs some renovation before they can move in this March.

Mr Richens, 59, who made his fortune in the insurance business, said: "It's a schoolboy dream to own a place like this. It looks like a fairytale castle."

He was born and brought up in Carterton, Oxfordshire's newest town, where historic buildings date only as far back as the 20th century. He added: "It's going to be a fantastic passion to restore over the next two to five years."

The self-made millionaires are well-known in Witney where for more than 30 years they ran FM Green insurance brokers at Market Square. It was bought out by the Bollington Group, of which Mr Richens is now a director - although he plans to retire in November.

He went to Burford School and then into the insurance business. He started at the Royal Insurance office in Oxford, before taking over FM Green at the age of 23.

His wife joined him to run the office, overseeing the accounts. Mr Richens still goes into the Witney office twice a week and yesterday was attending the funeral of 102-year-old Jack Room, a long-time associate at FM Green.

Mr Richens said: "We are self-made millionaires, but we are not trying to tell the world about it by buying a big property. It is really the Englishman and his castle dream. I've always been interested in history.

"We spotted it for sale and the fourth time we went to visit it, we thought this was for us. It's not been lived in for years, so needs a lot doing to it.

"It's been leaking through the roof, so the plaster ceilings are in a bad way. It's going to be great to have our grown-up children and their families, including grandchildren, to come and stay."

Rodborough Fort went on the market last August as a Grade II listed Victorian Cotswold folly with six bedrooms and nine acres.

The fort, which dates back to the early 1760s and boasts battlemented walls and turrets, was built for Captain George Hawker.

It housed a garrison of 250 men and 32 cannon to keep law and order in the countryside, before Stroud businessman, Alexander Halcombe, rebuilt it in 1870 as a two-storey folly with a tower.

In 1937 it was left to the National Trust, and in 1956 the fort housed refugees from the Hungarian revolution. The trust sold it in 1995 to a father and son, who have moved to Malawi to launch a mobile phone network.