Through his role as tour guide, Teddy was able to take families on incredibly emotional journeys at Thiepval.
He said: “Somebody would come to me with very little information about what happened to a family member and, with the knowledge that I had, within a very short time I could take them to the spot where their loved one died.
“You’re putting families in touch with more information than they had or ever expected to have. It’s very emotional.”
In 2015, three bodies were found close to the Ulster Tower. One of those men was Sergeant David Harkness Blakey of Royal Inniskilling Fusiliers.
Teddy said: “His school in Gateshead came for a tour of the wood and then got in touch with me to say the children had been so inspired by learning his story that they marked the 100th anniversary of his death by renaming a building in school after him.”
Teddy commented: “The story of the Somme is still very much alive today.”
He added: “George Gillespie was one of the men wounded by the grenade that killed Billy McFadzean VC. I was doing a tour for a Lurgan school and a girl put her hand up to say George Gillespie was her great grandfather.
“You can still meet family of people who served in WWI.”
The 80-year-old said he had become friends with the sons of a Londonderry soldier who fought his way into the German trenches at Thiepval Wood where he was shot and expected to be killed.
In a twist of fate he was taken to a German hospital and nursed back to health.
“When I first met his sons I thought, ‘How could a man fighting in the First World War have two sons younger than me?’ It turns out, long after the war, he’d married a 20-year-old when he was in his 70s.”
In terms of VIP visitors, motorsports commentator Murray Walker and former deputy first minister Martin McGuinness are among those who have enjoyed the warm hospitality of Teddy and Phoebe Colligan.
Phoebe said: “Murray Walker called one day. He said, ‘I haven’t much time, I’ve only about half an hour’.
“He stayed two and half hours. He got talking to Teddy about motorbikes.”
Last year for the 100th anniversary of the Somme a number of politicians from Northern Ireland visited the Ulster Tower. Teddy said Martin McGuinness was particularly impressed by the tour.
“Martin McGuinness was very respectful,” he said. “He was very interested and said he’d really enjoyed the tour.
“He sent me an 80th birthday card and a lovely personal letter after the visit.”
“He said he liked my egg and onion sandwiches,” Phoebe added.
The couple said that other well known visitors have included Prince Charles, Judi Dench, Michael Palin, Nigel Farage and Helen Skelton, as well as a number of senior religious figures.
Antiques Roadshow presenter Paul Atterby, whose great uncle is commemorated on Thiepval memorial, is a regular visitor and has become good friends with the Ulster couple.