One of the most important episodes in the history of gender reassignment surgery took place in Bristol, according to research for a historical exhibition taking place next month.

In 1942, a house surgeon at the Bristol Royal Infirmary carried out an operation on Michael Dillon - christened Laura Dillon - the first procedure of its kind in the world. This remarkable first is just one of the findings unearthed by volunteers for the OutStories Bristol project for 'Revealing Stories', Bristol's first ever exhibition of lesbian, gay, bisexual and trans (LGBT) history.

OutStories Bristol, a not-for-profit community group, has been tracking down the stories of LGBT people in Bristol. The research and exhibition have been made possible by a £20,300 grant from the
Heritage Lottery Fund.

Laura Dillon was born into an aristocratic family in Dublin in 1915. He later wrote that by the time he was studying at Oxford he was sure he was dressing and behaving as a man. "People thought I was a
woman. But I wasn't. I was just me."

Moving to Bristol to work at a neurology lab, Dillon tried to join women's branches of the armed forces when war broke out in 1939, but was turned down. Instead he worked at a garage in the city for four
years. (OutStories research indicates that this was at College Motors, Rupert Street.) At this time a local GP, George Foss, supplied Dillon with testosterone pills to begin his transformation. He was being treated for the side-effects of these pills at the Bristol Royal Infirmary when he confided in one of the hospital house surgeons. This doctor's identity is unknown, but he carried out a double mastectomy on Dillon and helped him change his name and official identity from Laura to Michael.

While living in Bristol Dillon wrote a book, Self: A Study in Ethics and Endocrinology, which outlines many of the principles by which transsexuals are still treated to this day. Dillon studied at the Merchant Venturers Technical College in Bristol before going on to medical school at Trinity College, Dublin. During college vacations, Dillon underwent further procedures with the pioneering plastic surgeon Sir Harold Gillies at a hospital near Basingstoke.

Dillon qualified as a doctor in 1951 and worked in a Dublin hospital. He also assisted Roberta Cowell, who had been born male and was Britain's first male-to-female transsexual to have surgery.

Michael Dillon later joined the merchant navy, working as a doctor on various ships and writing poetry in his spare time. Though he desperately wanted to live a quiet life, the Daily Express spotted the
anomalies in his entries in Burke's Peerage when he inherited his father's baronetcy (how could someone born a girl become a baronet?) and exposed him.

Michael Dillon decided to retreat from the world and went to India, gave away all his possessions, and became a Buddhist monk. He died in 1962.

"Michael Dillon's story is a remarkable tale of courage, and of a pioneering first that Bristol should be proud of," said Cheryl Morgan, co-chair of OutStories. "Thanks to Dillon and the kindness of two
Bristol doctors, trans people all over the world now have access to medical treatment that changes their lives substantially for the better."

Andy Foyle, OutStories' other chair, said: "Michael Dillon's is just one of the fascinating stories that have come to light when we were researching Bristol's LGBT heritage for the Revealing Stories
exhibition. This is just one small part of the hidden history of up to a tenth of the city's population, and we hope as many people as possible will come along to find out more."

Revealing Stories will be at Bristol's M Shed museum throughout February 2013. For further information see www.outstoriesbristol.org.uk and the OutStories Bristol Facebook page.