The 80th anniversary of Lancashire County Council’s archive service will be celebrated on Sunday 1 March.
The event will get under way at 11am and finish at 3pm, on Bow Lane, Preston.
Free activities, on a family and local history theme, are planned to mark the celebration.
Lancashire people looking to trace their roots will have plenty of advice available from family and local history societies, local archive services and other organisations. More experienced genealogists will have the chance to enjoy some hands-on practical online family history surgeries with Preston Family History Society.
Budding ancestry researchers will also be able to take part in short beginners workshops.
The family history of famous Lancastrians, Eric Morecambe, John Inman and Jeremiah Horrocks, will also be on display.
Behind the scenes tours will also take place.
County Councillor Peter Buckley, Lancashire County Council’s cabinet member for community and cultural services, said: “I’m sure that this will be a really enjoyable event.
“We’ll also have some of our most important archives on display and there will be ‘behind the scenes’ tours taking place to give people the chance to find out more about what we do.
“Also celebrity family history secrets might come to light, as the research in to the ancestry of some famous Lancastrians – Eric Morecambe, John Inman and Jeremiah Horrocks will be displayed!”