A historical treasure valued at $30,000 depicting an 18th-century governor now has a place of pride at the Bermuda Historical Society after a surprise donation.

A portrait of William Browne from his days as a student at Harvard University has gone from a Pennsylvania home to the walls of the society’s headquarters on Queen Street in Hamilton.

BHS president Andrew Bermingham called it a “treasure”.

“Not often, out of the blue, does someone ask if we’d be interested in an antique,” he said.

William Browne, originally from Salem, Massachusetts, was a judge whose political sympathies ran counter to the American Revolution against the British.

He ended up being forced out and his property was seized — but the British Prime Minister, Lord North, appointed him to govern Bermuda, where he served from 1782 to 1788.

Mr Bermingham said the society’s acquisition of the painting began this June with a one-line e-mail from Judi Wilson from Pennsylvania, asking if the BHS was interested in a gift of a Joseph Blackburn painting of Mr Browne.

The painting was being donated by Ms Wilson’s mother, Judith Herdeg, from Chadds Ford, Pennsylvania.

The family had researched the figure in their painting and discovered from a lecture at the Winterthur Museum, Library and Gardens in Delaware that Bermuda lacked a portrait of the governor.

Ms Wilson told the society: “As my mother’s health has declined, she was insistent that Mr Browne should find a home where he will finally be truly appreciated and honoured for his role in his world.”

Mr Bermingham said the society “jumped at the offer”.

John Cox, the BHS secretary and vice-president, said the valuable painting was “a fine 18th-century portrait of Massachusetts native, William Browne, painted by itinerant artist Joseph Blackburn, who also painted a number of prominent Bermudians between 1752 and 1753”.

“William Browne was an American loyalist who left New England at the start of the American War of Independence and landed in Bermuda where, to the island’s great credit, he became its governor and commander-in-chief.

“Through his daughter, Anne (Browne) Tucker, Governor Browne leaves a number of Bermudian descendants to the present day.”

One such descendant happened to be Sergeant Sean Morris of the Bermuda Police Service, a member of the society, who detected the familiar name this summer in the excitement over getting the portrait shipped to Bermuda.

Mr Browne was his sixth great-grandfather, Mr Morris said.

“I have to give credit to my cousin, James Masters, who is interested in genealogy and researched it,” he said.

“The only real information I have about him is that while he was here, he encouraged whaling, cotton production and shipbuilding.”

Mr Browne extolled the “superiority” of Bermuda’s ships and sailors, and built trade with the newly independent United States.

Mr Morris said: “Apparently with the public finances flourishing and the population up, he retired to London.”

He said he had tracked some of his ancestors back to 1066 in England, but “this was a new one”.

“The portrait is a lot clearer and in better condition than some of our other portraits.”

Mr Morris could not detect any family resemblance, however.

Mr Bermingham said the portrait had gone to “a place of honour where it will be on view to scores of visitors and residents alike as an educational and decorative monument to Bermuda’s rich past”.

The portrait was shipped with a formal deed of gift from Ms Herdeg, along with research papers by her husband, John Herdeg.

Ms Wilson said she planned to visit Bermuda with her husband to admire the painting in its new home.

The portrait was appraised over the summer, using comparisons with other portraits by Joseph Blackburne, at $31,637.

Mr Bermingham thanked the family profusely, saying such donations typically went to better-known galleries.

Special thanks also went to Richard Amos, the Acting Collector of Customs, along with customs officer Dean Lema and Dwayne Robinson of Best Shipping.