Demonstrating once again that fact is sometimes stranger than fiction is the story behind an 18th century painting now hanging in the Bermuda National Gallery. The English portrait has been found to have an unexpected Bermuda connection.

Around 1780, the Cornish artist, John Opie, R.A., sometimes referred to as "Cornwall's Reynolds'', had been given 25 and a new suit of clothes by the Prideaux family of Truro, Cornwall to pursue his art career in London. Now, some 200 years later, one of Opie's works has been placed in the room that houses the National Gallery's pivotal Watlington Collection. And it has just been revealed that the late Hereward Watlington's niece, Rosemary, is married to Mr. Denis Glynn, a cousin of that Cornish family who first recognised and encouraged Opie's talent.

"I was very interested to hear that the work of John Opie is going to be represented in the National Gallery,'' says Mr. Glynn. He feels that there is a double interest in this work, first, because it is by one of Britain's most famous portraitists and also, because of the subject of the painting.

It depicts Charles James Fox, Britain's first foreign secretary and leader of the Opposition for many years against William Pitt.

"I think our American visitors would be interested in this painting because he was very sympathetic to the American colonies,'' says Mr. Glynn. The picture was presented to the Bermuda Society of Arts by the late Nat Simpkins before he left the Island in the late 1960s.

For some years, it hung in City Hall but during the course of various renovations, the frame was damaged and the picture was set aside.

It was only when the Corporation of Hamilton was about to have the painting restored that it was found that it actually belonged to the Society of Arts.

As the Society curator, Mrs. Mac Musson points out, "It was the original aim of the Society to collect works of art to form the nucleus of a national gallery for Bermuda. Presumably, this is why the late Nat Simpkins presented the portrait to the Society.'' Mr. Michael Cowell, presently engaged in restoration work on the Watlington Collection for the National Gallery, made surface repairs to the portrait before it was hung in the Watlington Room. Although complete restoration would cost around $2,000, he estimates that the painting would fetch something in the region of $60,000 at auction.

Charles James Fox is one of the more colourful political figures of British history, who undoubtedly suffered unpopularity with his sovereign, George III because of his warm support of the American Revolution and later, his initial enthusiasm for the French Revolution.

Fox also deserves recognition for his success in steering through the English Parliament in the early 1790s, a resolution pledging the "speedy'' abolition of slavery.

The artist, John Opie, was the son and grandson of Cornish carpenters and attended the village school. It was soon apparent that he was something of a genius: by ten years of age he was happily solving the problems of Euclid and by twelve, had set up an evening school where he taught men twice his age. An early talent for drawing was soon followed by experiments in painting portraits which led to commissions from the country gentry.

"Opie began painting at a very early age. He painted almost everyone at Prideaux, even the cats and dogs,'' says Mr. Glynn.

PORTRAIT of Charles James Fox at the National Gallery.