The house in Neville Terrace was home to a succession of solidly middle- class, respectable types: a widow; a wine merchant; a civil engineer; a professor of music; and a colonel who had an illustrious career with the Indian police in the Punjab.
It helps that the three-bedroom house, with leaded bow windows and staff flat, is such a substantial affair. Cluttons is asking pounds 985,000 for the freehold. The histories of other homes with a faster turnover - where some tenants may have wished to avoid the official census - are harder to track.
"It helps a sale a great deal to know the history of the property," says Philip Green, of Goldschmidt and Howland. "We have a research department specifically to find out the history before we put a house on the market. An interesting history may encourage more viewers, leading to competitive bidding."
Blue-plaque houses have a slight edge on their neighbours, even though no one may have a clue about the allegedly important former occupant. G&H are currently selling a pounds 1.1m house in Howley Place, London W2, with a blue plaque dedicated to the Indian philosopher Tilak Lokamanya. More famously, the composer Gustav Holst lived in The Manse - then called The Steps - a Grade II* listed townhouse in Thaxted, Essex. Here he wrote his choral symphony. The four-bedroom house is on the market through Bruce Munro at pounds 260,000.
Notorious "black plaque" addresses can be no less attractive, says Philip Green cheerfully. "We have sold houses where people have been murdered ... one, in fact, where someone was hacked to death in the hall. It's something to talk about at your dinner parties."
But murders are acceptable only if there's been a decent interval between the police moving out and you moving in. Owners who pay to have the history of their homes researched want more for their money than a list of clean- living bankers, barristers and accountants. Adulterers, forgers, embezzlers and bigamists provide richer dinner-party fare.
Which owner of 9 Berkeley Street, Mayfair, could resist dropping in conversation that the house was once lived in by Elizabeth Howard, mistress of Jem Mason - the jockey who won the first Grand National in 1839 - and later of Louis Napoleon, emperor of France? A flat in Portsea Hall near Hyde Park, on the market through Chestertons at pounds 127,500, may pick up extra viewers because the spy Anthony Blunt lived in the block, and Lord George Brown also had a flat there.
"The past is powerful in us all," says Colin Style, a professional house history researcher. "And people get curious about their homes, once they've moved in." He and his wife O-Lan have spent nine years digging up the secrets of homes from Middlesex to Cornwall. "It can be deadly dull," warns Colin. "You may find generations living serene and harmonious lives with not a hint of vivid drama."
Researchers charge several hundred pounds for a full history. "People are sometimes surprised at the cost, but it may take two of us two weeks. Imagine what it would cost to have the plumber in that long." You can research the history yourself, but it can be confusing if you don't know where to look. Some parish records are more complete than others, but the census office is a good starting-point.
Some Norman, French and medieval Latin could also be useful, suggests Colin, and a good eye for deciphering bad handwriting and erratic spelling. Their own house turned out to hold some unwelcome surprises. "We thought it was Georgian, but then found a map that showed it as a blank space in 1887. In fact it is a Victorian cottage, built in 1902."
And what about worries over former occupants who won't go away? Ghosts, he says, are out as far as clients are concerned. "People really do not want to know about them. But after we'd had some damp-proofing done in our house, I was standing in the kitchen when I felt a rush of warm air and heard an old lady's voice chattering in my ear. I have to tell you it made my hair stand on end."