Media playback is unsupported on your device Media caption "My own darling boy" - a greeting in one of the letters

While on military training during World War Two, Gilbert Bradley was in love. He exchanged hundreds of letters with his sweetheart - who merely signed with the initial "G". But more than 70 years later, it was discovered that G stood for Gordon, and Gilbert had been in love with a man.

At the time, not only was homosexuality illegal, but those in the armed forces could be shot for having gay sex.

The letters, which emerged after Mr Bradley's death in 2008, are therefore unusual and shed an important light on homosexual relationships during the war.

What do we know about this forbidden love affair?

Wednesday January 24th 1939

My darling,

... I lie awake all night waiting for the postman in the early morning, and then when he does not bring anything from you I just exist, a mass of nerves...

All my love forever,

G.

Information gleaned from the letters indicate Mr Bradley was a reluctant soldier. He did not want to be in the Army, and even pretended to have epilepsy to avoid it.

His ruse did not work, though, and in 1939 he was stationed at Park Hall Camp in Oswestry, Shropshire, to train as an anti-aircraft gunner.

He was already in love with Gordon Bowsher. The pair had met on a houseboat holiday in Devon in 1938 when Mr Bowsher was in a relationship with Mr Bradley's nephew.

Mr Bowsher was from a well-to-do family. His father ran a shipping company, and the Bowshers also owned tea plantations.

When war broke out a year later he trained as an infantryman and was stationed at locations across the country.

February 12 1940, Park Grange

My own darling boy,

There is nothing more than I desire in life but to have you with me constantly...

...I can see or I imagine I can see, what your mother and father's reaction would be... the rest of the world have no conception of what our love is - they do not know that it is love...

But life as a homosexual in the 1940s was incredibly difficult. Gay activity was a court-martial offence, jail sentences for so-called "gross indecency" were common, and much of society strongly disapproved of same-sex relationships.

It was not until the Sexual Offences Act 1967 that consenting men aged 21 and over were legally allowed to have gay relationships - and being openly gay in the armed services was not allowed until 2000.

The letters, which emerged after Mr Bradley's death in 2008, are rare because most homosexual couples would get rid of anything so incriminating, says gay rights activist Peter Roscoe.

In one letter Mr Bowsher urges his lover to "do one thing for me in deadly seriousness. I want all my letters destroyed. Please darling do this for me. Til then and forever I worship you."

Mr Roscoe says the letters are inspiring in their positivity.

"There is a gay history and it isn't always negative and tearful," he says. "So many stories are about arrests - Oscar Wilde, Reading Gaol and all those awful, awful stories.

"But despite all the awful circumstances, gay men and lesbians managed to rise above it all and have fascinating and good lives despite everything."

February 1st, 1941 K . C. Gloucester Regiment, Priors Road, Cheltenham

My darling boy,

For years I had it drummed into me that no love could last for life...

I want you darling seriously to delve into your own mind, and to look for once in to the future.

Imagine the time when the war is over and we are living together... would it not be better to live on from now on the memory of our life together when it was at its most golden pitch.

Your own G.

Image copyright Oswestry Town Museum

Image copyright Oswestry Town Museum

But was this a love story with a happy ending?

Probably not. At one point, Mr Bradley was sent to Scotland on a mission to defend the Forth Bridge. He met and fell in love with two other men. Rather surprisingly, he wrote and told Mr Bowsher all about his romances north of the border. Perhaps even more surprisingly, Mr Bowsher took it all in his stride, writing that he "understood why they fell in love with you. After all, so did I".

Although the couple wrote throughout the war, the letters stopped in 1945.

However, both went on to enjoy interesting lives.

Mr Bowsher moved to California and became a well-known horse trainer. In a strange twist, he employed Sirhan Sirhan, who would go on to be convicted of assassinating Robert Kennedy.

Mr Bradley was briefly entangled with the MP Sir Paul Latham, who was imprisoned in 1941 following a court martial for "improper conduct" with three gunners and a civilian. Sir Paul was exposed after some "indiscreet letters" were discovered.

Mr Bradley moved to Brighton and died in 2008. A house clearance company found the letters and sold them to a dealer specialising in military mail.

The letters were finally bought by Oswestry Town Museum, when curator Mark Hignett was searching on eBay for items connected with the town.

He bought just three at first, and says the content led him to believe a fond girlfriend or fiancé was the sender. There were queries about bed sheets, living conditions - and their dreams for their future life together.

Image copyright Oswestry Town Museum Image caption Gilbert Bradley was stationed at Park Hall Camp in Oswestry in 1939

When he spotted there were more for sale, he snapped them up too - and on transcribing the letters for a display in the museum, Mr Hignett and his colleagues discovered the truth. The "girlfriend" was a boyfriend.

The revelation piqued Mr Hignett's interest - he describes his experience as being similar to reading a book and finding the last page ripped out: "I just had to keep buying the letters to find out what happened next."

Although he's spent "thousands of pounds" on the collection of more than 600 letters, he believes in terms of historical worth the correspondence is "invaluable".

"Such letters are extremely rare because they were incriminating - gay men faced years in prison with or without hard labour," he says. "There was even the possibility that gay soldiers could have been shot."

Work on a book is already under way at the museum, where the letters will also go on display.

Perhaps most poignantly, one of the letters contains the lines:

"Wouldn't it be wonderful if all our letters could be published in the future in a more enlightened time. Then all the world could see how in love we are."