English Heritage has launched a campaign to rediscover 50 missing blue plaques across London honouring great Britons.
Among the missing blue plaques are ones commemorating William Hogarth, John Milton and Joseph Lister.
The charity said many plaques have gone missing over the decades because of war damage, demolition, or building work, reported The Guardian.
Even the very first plaque awarded under the scheme in 1867 to honour poet Lord Byron went missing after his birthplace was demolished near Cavendish Square in 1889.
The distinctive ceramic tile could be in the foundations of nearby John Lewis on Oxford Street.
English Heritage has said it is keen to see any of the surviving missing plaques returned so that they can be reinstalled onto a different address, or conserved.
Most of the missing plaques will be dated from the time that London County Council ran the scheme, meaning it will bear their name or the initials LCC.
They may also be brown or terracotta in colour, as opposed to today’s distinctive blue.
“These lost plaques are still part of the story that the London blue plaques scheme has been dedicated to telling for the past 158 years,” said the English Heritage curatorial director, Matt Thompson told the paper.
“The story, not just of London, but of the breadth of human endeavour.
“Whether they are on a building for all to see or safely in our stores along with others already returned to us, each plaque documents the history of what is arguably the oldest commemorative scheme in the world.
“That is why we would like to find out if any of the ‘lost’ plaques survive and why I’m so delighted that one of the pioneers of modern surgery, Joseph Lister, gets another chance to be commemorated.”
