What began as a youthful curiosity about a grandfather's tales became a detective story of yellowing papers and dusty public records.

Albert Gearing has spent the best part of three decades researching his family history and has traced 15 generations of Gearings back to the early 16th Century.

Now he has published a book entitled From Sussex Yeomen To Greenwich Watermen, that chronicles the story of the Gearing family through the male line during the last 500 years.

Mr Gearing, 75, from Keymer, near Hassocks, said: "Sometimes I felt like a detective. You have to do a lot of research which often goes nowhere but when you find something it's exciting. It's like finding the missing piece in a jigsaw puzzle.

"Any family historian who gets further than the 18th Century is doing very well. I was able to go back even further because my family left a lot of records. I discovered we have been in Sussex for hundreds of years."

His interest in the family's history was sparked as a youngster by his grandfather's tales. John Henry Gearing was in the Merchant Navy and spent time as a gold miner in Australia.

Mr Gearing, a retired hotelier, said: "My grandfather was born in the 1850s and died at 90, so I remember him well and he told me a lot about his father and grandfather, who was born in 1798."

His initial research was fairly easy as the four previous generations had been mariners or river pilots based in Greenwich.

It was not until somebody mentioned the large number of Gearings in Sussex that Mr Gearing decided to investigate further.

Through research at the Society of Genealogy in London, the Public Record Office in Kew and libraries, he discovered the family's Sussex connection.

He traced as far back as Richard Geeringe, who was born in Patcham around 1500, when Henry VIII was still a boy.

Richard's descendants went on to own land and windmills north of the fishing village Brightlesmeston, as Brighton was known then.

The family continued to live in the area until William Geering, who lived in Clayton, sailed to Greenwich in 1795, where the family settled for 200 years.

Mr Gearing said: "I was fascinated to find the family originally came from Sussex. Because they were established yeoman, a lot of our history is recorded in records on property dealings and court cases in which they served as jurors."

Despite his discoveries, Mr Gearing only decided to write a book three years ago after being approached by a publisher.

He said: "I had made a lot of notes over the years and always thought they would end up in a skip after my death. My niece kept encouraging me to write a book until I thought 'Why not?'.

"I did it for the family but I am delighted other people have found it interesting. It's nice to read the history of a normal English family rather than the aristocracy or royals."

Mr Gearing, who does not have children, hopes the book might help him trace Gearings who could be long-lost relatives.

He said: "Unfortunately, I am the last in the line. So far I have not been able to find a single surviving male Gearing in our family. I would love to find a Gearing and prove we are related. It's an unusual name but I know there are a lot in the Sussex area."

After several years working as a hotelier in Jersey, Mr Gearing decided to move to Sussex when he fell in love with it through his historical research.

When his parents died, Mr Gearing decided to have them interred in Clayton churchyard, near his present home.

He said: "The family has come full circle. My father is back with his ancestors.

"Even though my recent family came from Greenwich I feel my roots go back further and belong here."

From Sussex Yeoman To Greenwich Watermen is published by Country Books, priced £10.