A long-lost short that was screened ahead of the original run of Star Wars sequel The Empire Strikes Back is to be shown in the UK for the first time in more than three decades, according to the BBC.

Fantasy story Black Angel was specially commissioned by Star Wars creator George Lucas to be screened with his 1980 blockbuster in European cinemas. Shot on location on the tidal island of Eilean Donan in the western Highlands of Scotland, it is described as an Arthurian tale of a knight who rescues a princess on his way home from the Crusades.

The original prints went missing after Empire's run in cinemas, but turned up in the archives of Universal Studios in the US two years ago. Now the film, directed by Oscar-winning Star Wars set designer Roger Christian and shot for just £25,000 using equipment and film stock borrowed from Lucas's shoot, is to be shown at the Glasgow film festival later this month.

Christian, who later worked on Return of the Jedi and prequel The Phantom Menace, has wonderful memories of heading into the Highlands with only a Volkswagen camper van, a horse trailer and a small van.

"With just the vans and a horse trailer we were able to get right into these beautiful locations," he told the BBC. "For me Eilean Donan Castle is the ultimate romantic castle, while the landscape of Kyle of Lochalsh is spectacular. We went in September and October because the light in Scotland then is fantastic. But in the back of my mind I knew that at any time winter could come and end the filming."

A restored version of Black Angel was shown last year at October's San Francisco's Mill Valley film festival, but it has not been shown publicly in the UK in its original format since 1980. "I had my own copy, but it was a degraded copy," said Christian. "I preferred Black Angel become a myth rather than show a poor quality version of it."

Following its screening in Glasgow, Black Angel is expected to be available for download and streaming on iTunes and Netflix.