Peter Jackson link to Tolkien revealed

It's only natural Peter Jackson became obsessed with J.R.R. Tolkien - the film-maker's granddad had a brush with the author once upon a time.

As Anzac Day approaches, research reveals a special surprise for Jackson.

Ancestry.com.au family historian Christine Clement said the story began in World War I with William John Jackson, the Wellington director's grandfather. Clement said William fought at the bloody Battle of the Somme with the South Wales Borderers' second battalion.

On July 24, 1916, a young Tolkien arrived at the Somme. He would share many of William's frontline experiences.

"[William] did some reconnaissance work over there," Clement said. "His battalion was relieved by the 1st Lancashire Fusiliers, who Tolkien was with."

William, born in 1889, survived the war and won a Distinguished Conduct Medal for his efforts on the Western Front.

Clement believed her findings would be news to Peter Jackson. "He knows about his grandfather having the DCM but not that Tolkien was there."

Tolkien went on to publish The Hobbit, a prelude to his Lord of the Rings trilogy, in 1937.

William John Jackson died in England in 1940 while his son, William Arthur, was serving in World War II.