A teenage Megan Cole beamed with pride as she marched with the Australian Army Cadets youth organisation through the streets of her hometown in Queensland, Australia. Her troop was part of the parade celebrating Anzac Day, the national holiday commemorating Australia and New Zealand’s military actions during World War I. She’d followed in the footsteps of her older brother, joining the cadets as soon as she turned 13, and relished the adventures and opportunities it brought.

Growing up in the bush town of West Wyalong in New South Wales, Mat McLachlan was also enamoured with the military. “My grandfather served in World War II, during which his brother was killed in action, so we were brought up appreciating soldiers’ sacrifices,” he recalled. “I remember watching the veterans marching on Anzac Day, feeling fascinated by the stories they would tell and filled with a desire to learn more.”

Neither would ever imagine this shared love of the military would impact their future in so many ways.

Cole and McLachlan’s interests evolved into their careers. Cole joined the Royal Australian Air Force where she piloted an AP-3C Orion on anti-smuggling patrols, hunts for pirates in the South China Sea and on search and rescue missions for refugees.

McLachlan pursued a career in journalism with an emphasis on military history. He authored several books on the Australian experience and eventually founded Battlefield Tours, a company that leads historical tours of battlefields across the world.

“When you’re walking through the same spot where a battle occurred, you traverse the landscape and experience the climate that would have had major impact on the soldiers. You visit the graves of the people who lost their lives, and you make an emotional connection to the history,” he said.

This type of first-hand experience appealed to Cole, who was particularly fascinated with visiting Gallipoli in Turkey, the site of an important battle fought by Australian and New Zealand forces during World War I, which Anzac Day commemorates.

“Marching with the cadets on Anzac Day was so special, and I had decided as a teenager that I wanted to go Gallipoli for the 100th anniversary in 2015,” she said. Despite Gallipoli’s remote location six hours south of Istanbul, it holds such historical significance for Australians that it’s frequently visited, particularly on the 25 April holiday.

“I began to look into it at the start of 2012 and learned that they were already limiting the number of people for the 100th anniversary. So at the last-minute I decided to go over Anzac Day in 2013 to be sure I would be able to experience the holiday there,” Cole said.

She joined a tour operated through McLachlan’s company, and while he wasn’t the historian in charge of the group, he happened to be in Gallipoli at the same time researching a book.

They first saw each other at the Tusan Hotel. “Mat had just arrived that night and he came around to the tables where we were having dinner to introduce himself to the group,” Cole said. “I had read a little about him online when I researched the tour, and I had an idea in my head about what I thought he’d be like. I think there’s often a perception that historians are a bit old, but when I first saw him, I remember thinking he was much younger than I expected.”

After dinner, they sat down at the hotel bar, and quickly found themselves lost in conversation. “He knew so much about the history of the military, but not as much about the current military and was really interested in what I had to say,” Cole remembered. “We hit it off right away.”

McLachlan was struck by his good timing. “We give hundreds of tours a year, so obviously, I’m not travelling around on every one. It was truly a coincidence that I was in Gallipoli for research at the same time as Megan’s group. It was meant to be.”

Days were spent with the group exploring the battlefields. “Gallipoli is a wild and exposed place, a peninsula that sticks out into the Aegean Sea,” McLachlan said. “It’s very hot, dry, and mountainous. It’s difficult, for the soldiers who had to fight there in 1915 and for tourists who go there today, but I think that’s part of the appeal. You have to try hard to get there, and you get an amazing insight of the hardship experienced by the soldiers.”

“In saying that, though, it is stunningly beautiful,” Cole added. “The cemeteries are well maintained and there are flowers everywhere, even though it’s so isolated.”

When they returned to the hotel at night, “we would have a few drinks and talk about how the day affected us. We connected over the history and the emotions of being in this place,” McLachlan said.

Eventually the tour came to an end, and Cole and McLachlan parted as friends. She returned to her base in South Australia and he to Sydney, more than 1,500km away. But, they remained intrigued by one another, and within a year, social media exchanges and the occasional get together had blossomed into romance.

“We tried long distance, but then I moved to South Australia where Megan’s base was so we could be together,” McLachlan explained. 

“And, I got to the 100th Anniversary of Anzac Day in Gallipoli after all,” Cole said.

The couple made the trip together in 2015. “It was an incredible feeling to be there for the centennial,” McLachlan said. “There were thousands of people everywhere. My company alone took 2,000 people.” The celebration included a dawn service at Anzac Cove with tributes from Prince Charles and the then prime minister of Australia, Tony Abbott.

“And going back together to the place we’d met was so special,” he added. “We stayed at the same hotel, and had drinks together at the bar again.”

If you’re interested in history, you can’t walk through those battlefields without gaining perspective on what’s important in life. How quickly it can all change.

Cole and McLachlan currently live in Queensland and have spent the last year exploring battlefields in Vietnam, Germany, France and the US. “There’s no one I’d rather travel with than Megan,” McLachlan said. “I’ve never served in the military, so to have a partner that has that experience, who gives me input into what it would have been like for soldiers, offers an incredible perspective. We make a fantastic team.”

All that time spent exploring places where so many people never came home does stay with them.

“Some people are relaxing on beaches, but we’re walking around cemeteries learning these stories and seeing what’s written on headstones, sometimes with tears in our eyes,” McLachlan said. “If you’re interested in history, you can’t walk through those battlefields without gaining perspective on what’s important in life. How quickly it can all change.”

Added Cole, “We feel lucky to live in a country that’s at a time of peace, and with the person we love.”

If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.