George Orwell was born 100 yeras ago this week, but it's much more recently, and purely by chance, that his link with a house overlooking the Durham hills was discovered, a house where the beginnings of his famous novel 1984 may first have been formulated. Chris Lloyd reports.

FROM his chair in the bay window, George Orwell looked out over the gently rolling hills of Durham. On the skyline to the north, he could make out the four pinnacles of Sedgefield church tower like an upturned table in the distance; to the west, he could see the slender spire of Great Stainton church, rising gracefully through a gap in the trees.

On his mind as he sat in that sunny spot outside Stockton was the recent death of his wife on an operating table in Newcastle, the loss of his flat in London, which had just been destroyed by a German bomb, and the increasing problems with his own health - the tuberculosis that would kill him within five years was already apparent.

And in his mind as he stared out over a thorn hedge to the fields of Durham was the plotline that would link Winston Smith with Big Brother, thoughtcrime, doublethink and Room 101 in his seminal book, 1984.

Wednesday is the 100th anniversary of the birth of Orwell, the author who wrote two of the most important novels of the 20th Century, Animal Farm and 1984. The anniversary is being commemorated by the publication of two biographies about Orwell (the fourth series of Big Brother being constantly on the telescreen is probably coincidental), but neither book contains much about the 18 months that the writer Eric Blair spent overlooking the constituency that now returns Tony Blair.

Blair - that's Eric, who adopted the pen name George Orwell in 1932 - stayed at Greystone, a Victorian villa outside the village of Carlton, which is itself outside the town of Stockton.

In 1965, Frank Medhurst bought the villa. He had read Orwell in his university days in Bristol, and had just arrived in the district to carry out the Teesside Survey and Plan - the government's attempt to find a future for the area as the old industry declined.

In 1967, the plan completed, Frank was sacked. This was the era of T Dan Smith, and whereas Frank wanted to talk about the problems of "pollution", the authorities only wanted to refer obliquely to "atmospheric conditions".

In 1968, Penguin published three volumes of Orwell's collected essays, articles and letters. "I was sitting here with the view out of the window reading volume three when I saw this address, Greystone, Stockton-on-Tees," says Frank. "I knew nothing about it. In fact, what amazed me was that no one knew anything about it."

He discovered that in 1935, Orwell celebrated the publication of his novel The Clergyman's Daughter by having a friend organise a party in Oxford. One of the guests was Eileen O'Shaughnessy, who was born in South Shields, educated at Sunderland High School (where, incidentally, she wrote a poem about the school's 100th anniversary which was entitled End of the Century 1984, which may have inspired Orwell) and went to Oxford University. Within a year of the party, Orwell and Eileen were married.

By early 1937, they were in Spain where Orwell was fighting for a Marxist militia in the Civil War. A tall man at 6ft 6in, hunched trench warfare wasn't his strength and one morning, as he stood up, a sniper shot him in the throat. He was taken back to Barcelona where Eileen was waiting to nurse him. When the fascists closed in on the Catalan capital, Eileen and Orwell fled for their lives to France and then on to London.

In 1939, Orwell wanted to fight against Hitler, another fascist, but was declared physically unfit because of his throat problems and the onset of TB. Instead, he joined the Home Guard and the BBC. He wrote and published Animal Farm and, in 1943, mentioned to a friend that he had a germ of an idea for a novel to be called The Last Man.

Eileen and Orwell also adopted a son, Richard, which made life very difficult when their flat was bombed in a German air raid. Fortunately, early in 1944, Eileen's sister-in-law, Gwen, invited them to stay at Greystone.

Gwen was a Hunton - a family of Sedgefield doctors and Stockton solicitors whose home was Greystone. Her husband, Lawrence, a world-renowned chest surgeon, was Eileen's brother, but he had been killed at Dunkirk in 1940.

Eileen was obviously close to the Huntons. She had introduced Gwen's sister, Doreen, to Orwell's Marxist commander in the Spanish Civil War, a Russian revolutionary called Georges Kopp, and they had married.

So Greystone, where they were attended to by the housekeeper Gladys Blackburn whose husband was their chauffeur, became a happy refuge from the troubles of war for the Orwells.

Before she died, Mrs Blackburn told Frank Medhurst that she knew the guests only as "Mr and Mrs Blair". "She said that he would sit in the corner staring out of the window over the fields for hours on end," says Frank. "He wouldn't go down the pub or for walks in the country with the others. He just sat there, sometimes making notes."

Could it be that those thoughts and those notes were the beginnings of The Last Man which, when it was published four years later, appeared under the title of 1984?

Orwell didn't stay long at Greystone. In early 1945, he was dispatched by the Observer newspaper to cover the liberation of France. His health quickly deteriorated and he wound up in hospital in Cologne suffering a severe lung infection.

Understandably, then, Eileen's letter of late March 1945, typed "on a warm spring day in the garden at Greystone while Richard sits up in his pram" is cheerfully gossipy. Only in passing does she mention that she would soon be going to Newcastle Infirmary for an operation - probably a hysterectomy.

She travelled up soon after going to the postbox, and on March 29 composed what would be her final letter from her hospital bed.

"Dearest," she began. "I am just going to have the operation, already enema'd, injected (with morphia in the right arm, which is a nuisance), cleaned and packed up like a precious image in cotton wool and bandages. When it's over I'll add a note to this and it can get off quickly.

"This is a nice room - quite low so one can see the garden. Not much in it except daffodils and some crocus but a nice lawn. My bed isn't next to the window but it faces the right way. I also see the fire, the clock..."

Here Eileen either drifted off as the morphia took effect, or the nurses came to wheel her away. Either way, she never completed her letter as she died on the operating table - there was an error with the anaesthetic. She was 40.

The Observer cabled Orwell with the terrible news. He drugged himself up, discharged himself from hospital and sped from Cologne to London and on to Greystone. There, as he opened the front door, on the hall table was the unfinished letter from Eileen.

How the worries of the world must have crowded in on him as he sat for a few dreadful days at Greystone. There was Eileen's funeral to arrange (she was buried in Jesmond, Newcastle); there was Richard's future to sort out (he was adopted by Doreen, the doctor's daughter from Sedgefield, and Kopp, the Russian revolutionary). There was his own health to worry about - he was coughing and spitting blood - and there were ideas and notes for his new book nagging away at the back of his mind.

After the funeral, Orwell packed up at Greystone and severed his ten-year association with the North-East - an association that had brought him love, happiness, security and ideas, but which had ultimately ended in tragedy.

He spent nine months in London before retreating to an isolated farmhouse on the remote Scottish island of Jura. Pounding away on a typewriter and coughing terribly as his lung illness worsened, Orwell wrote the novel he was still calling The Last Man. By early 1947, he had completed it and returned from his exile to find a publisher. The publisher suggested that the last two digits of the year in which the book was due to appear, 1948, should be reversed to give the title a futuristic feel.

Orwell's health was deteriorating and he died in January 1950 in London, aged 47.

Frank Medhurst finishes telling the story of George Orwell and Greystone in the room where the writer spent those missing months staring out over the thorn hedge towards Sedgefield and Great Stainton.

Frank says: "When I told the curator of Middlesbrough museum the story, he said I had to do something about it, but I couldn't interest anyone official in it, so I had the blue plaque made up myself."

The plaque records the bare facts - "George Orwell, novelist, essayist, critic, lived here, 1944-1945" - but can't tell what great literary thoughts might have occured here at the same time.