Ashton, 61, was a history teacher, housemaster and sports coach at King's Bruton School in Somerset from 1987 until 1995.
In his final year at King's Bruton, the independent school's first XV were in trouble: they couldn't compete at the line-out so Ashton suggested players avoided kicking to touch. The team went on to win 11 of its 12 games, beating arch-rivals King's College in Taunton for the first time in 26 years.
Simon Atkinson, King's Bruton's head of science, helped Ashton to coach the team. Despite the "no kicking" rule, he felt there were similarities between the school's tactics and England, which transformed its World Cup fortunes after a dismal start.
"It was a fantastic achievement for a school with only 350 pupils," he said. "We had what was described as an attack-at-all-costs policy and the team kept on playing and playing and playing, no matter what happened. There's a nice parallel with what's been going on in the World Cup".
Mr Atkinson is still in contact with Ashton, who has texted him with updates from the competition in France. "He wanted the boys to set themselves the highest standards off the pitch as well as on," Mr Atkinson said. "His philosophy was that how you prepare for a match and perform on the pitch reflects how you lead your life."
From 1980 to 1988, Ashton taught at Stonyhurst College, a Catholic public school near Clitheroe in Lancashire. His pupils there included Kyran Bracken, a scrum-half in England's World Cup-winning squad four years ago.
"I really enjoyed teaching at Stonyhurst," Ashton told the school's website. "I have fond memories of teaching Kyran Bracken history, and I would like to think that I was largely responsible for helping him move up a stream."
His interest in his subject clearly remains: he invited Paul Garlington, head of the history at Stonyhurst, to take the England team on a tour of the Somme battlefieldwhen they arrived in France.
One of Mr Ashton's fellow coaches at the school in the 1980s was Dick Greenwood, father of Will, another Stonyhurst old boy who played in England's 2003 winning team.
Greenwood said he and Ashton had carefully constructed a range of rugby tactics for the boys.
"Some of the moves England will be relying on in France will have definitely been nurtured on the rugby fields at Stonyhurst College," he said.