The stain is real enough.

Glasgow’s global reputation remains tarnished by its legacy of profiteering from the Atlantic slave trade.

And the city still memorialises, in street names and statuary, some of the merchants and politicians who enabled or carried out mass people trafficking.

Merchant John Glassford, who owned slaves, has a street named after him. So too does Henry Dundas, the political strongman most historians blame for prolonging slaving.

And right in the heart of the city there is a monument to James Watt, the long-celebrated engineer who literally sold a boy called Frederick not far from where his statue stands now.

But is the blood of the victims of these men to be found in the built heritage of Glasgow? Not so much.

There are those who passionately - and perhaps understandably - believe that slavery must have paid for the sometimes ostentatious edifices which line George Square or the streets named after slave owners like Andrew Buchanan or Archibald Ingram.

But most of central Glasgow’s sandstone fabric is late Victorian, not Georgian. That does not mean the capital which paid for it cannot be traced back to 18th and early 19th century slaving. But links are rarely direct.

Take the City Chambers. The Beaux Arts seat of local government, the nearest thing Glasgow’s has to an iconic postcard building, was built in the 1880s. It comes complete with a pediment celebrating Britain’s imperial subjugation of other countries. But was it built with slave money? No.

Historian Stephen Mullen of Glasgow University is carrying out what is believed to be the UK’s first ever civic investigation in to the legacy of slavery. He had already carried out similar work for his employers, the University of Glasgow, which last week was named university of the year because of the way it handled its own legacy of slavery. The main building of the university on Gilmorehill, put up a decade or so before the City Chambers, did take funding from those who profited from the Atlantic trade.

Dr Mullen’s work has been delayed by the Covid pandemic. But, in an online conference organised by the council last week, the expert said he had already ruled out that bloody money paid for the marble and Italianate embellishments of the City Chambers.

“Speaking in very broad terms, the City Chambers were founded in the 1880s, half a century after slvery was abolished in the British west indies and a quarter of a century after slavery was abolished in the United States.

“That does necessarily preclude any involvement because we know the University of Glasgow was built in 1866-1870. The two funding strategies differed entirely. The University of Glasgow was a public campaign, was relatively small and private and relied upon gifts from former and current staff and students and notables.

“By the 1880s the Glasgow Corporation had an enormous municipal income, which facilitated both short and long term borrowing from banks. So there was no requirement to encourage public subscription from individuals in the way the university has recently acknowledged.”

Dr Mullen is continuing his work and city leaders are still looking at ways to mark Glasgow’s legacy of slavery - and imperialism.

This summer, in the heart of the Black Lives Matter protests, there were those who claimed, without evidence, that statues of those stained with people trafficking were somehow being threatened.

There were particular concerns over a monument to King William III, “King Billy”, who both personally profited from slavery and played a key role in developing the Atlantic trade. It was vandalised and them given police protection.

Some officials feared the statue, at Glasgow Cathedral, could become a flash point for trouble as “Culture Wars” imported from the United States became entangled with Scottish sectarianist strife. William after all is seen as both liberator - by some protestants and loyalists - and enslaver.

However, what city leaders are now seeking is a different sort of a focal point: a museum of slavery (and perhaps imperialism too).

Such an “attraction” may be a long time coming. There is little more than a vague desire to have such a venue in Scotland and little agreement over where it should be.

Graham Campbell, a Glasgow councillor who has been at the forefront of efforts to get Scotland to come to terms with the darker side of its history.

“Glasgow is the right place for a slavery museum but I would say that wouldn’t I?” Campbell told the same conference that Mullen addressed. “However, other places also have a good claim. If you look at where the slavery compensation was paid out to owners and pinpoint it on a map there is a lot of it in Edinburgh’s New Town.

“Greenock has made a pitch for this. It was in Port Glasgow and Greenock that the slave goods were landed. And it is with Greenock that James Watt is associated.”

Glasgow in September appointed a specialist curator to deal with slavery and imperialism in the city’s existing collections.

Campbell said he thought a national museum could end up having several locations. He said: “It has been the policy of the council to look in to a permanent exhibit in our museum estate.

“We may have to go down the same path and then develop [the local exhibit] in to a big national museum. It could be like the V&A or the Tate, which are multiple site galleries.”