One of the earliest known images of a black person by a Scottish artist was acquired by the National Galleries of Scotland.

The painting, which shows a black woman on an Edinburgh street, is dated to the mid-1980s and early 1990s.

It is unusual to show a black woman in the center of a scene rather than a marginal figure in a group portrait.

It is not known who the woman was, but her dress and churn suggest that she was a servant, perhaps a milkmaid.

Alloa-born artist David Allan created drawings of ordinary people going about their daily lives in Edinburgh, including soldiers, charcoal burners, fisherwomen, porters, firefighters and city guard officers.

These works, known as Allan’s “Characters of Edinburgh”, are very different from this detailed portrait of a specific person.

Christopher Baker, Director of European and Scottish Art at the National Galleries of Scotland, said: “We are so delighted to bring this extraordinary, rare and extraordinary watercolor to the Scottish National Collection.

“It is an incredibly surprising and special work, which we believe will be appreciated by many and, we hope, will lead to new research on his background and, above all, on the history of the woman depicted.”

David Allan was one of the first Scottish artists to paint contemporary life and customs.

With the support of his patrons, Lord and Lady Cathcart of Shaw Park, near Alloa, he traveled to Italy where he drew street scenes.

He took a similar approach when he returned to Scotland, and many of his drawings are already preserved in the collection of the National Galleries of Scotland.

Milkmaid with Butter Churn is currently undergoing conservation work, but will be exhibited at a later date.