A worldwide search is on for the dozens of people who may have an important role to play in the 2012 Preston Guild celebrations.
Guild burgesses were the merchants and traders who agreed to form a Guild in 1379. The membership is renewed every 20 years and passed down the generations.
But many people probably do not even realise they are entitled to burgess status and are being traced to play a key part in the 2012 party.
Sons and daughters of former burgesses are top of the list but council bosses are concerned it could prove difficult to trace them, particularly women who have married and have never been traced before because it was originally an all-male club.