February 12, 2015 4:18 PM EST

“There is something to photographing a kiss,” says photographer Lauren Fleishman, “especially of a couple who has been together for over 50 years.”

Fleishman’s latest book The Lovers, published by Schilt, documents the love stories of couples that have been together for over five decades.

It was inspired after her grandfather’s death when she discovered a trove of love letters he had written to her grandmother during World War II. The diary found next to his bed after his death held the letters that spoke passionately of a young love — the type of hopeful love Fleishman describes as “filled with expectations of their new life together.”

In one letter, her grandfather wrote, “I love you with all my heart, and will continue to do so for the rest of my life.” The letters felt timeless and instantly connected her to her grandparent’s 59-year marriage in a way that she had not been able to experience before. “They also inspired me to seek out and record the love stories of these long-term couples around the world,” says Fleishman.

When the project started, she set out to photograph 50 couples but it quickly grew to almost 100 couple around the world. On the second photo shoot, she asked the couple to kiss and in the moment she had an epiphany. “There was something perfect about how their face fit together,” she tells TIME. “In the media you just don’t normally see older people in this way. I wanted to connect people to these couples in the way that my grandfather’s letters connected me to him. I was getting so much positive feedback after sharing some of the early portraits and I realized that there was something useful about it; in a way that it can help to erase a lot of the boundaries that we have between younger and older people.”

It also helped the process of making subjects comfortable, she adds. “What I found is a remarkable sense of familiarity in that moment. Kissing helped the couples to relax in front of the camera. It allowed them to connect and remember. There is something in a kiss that allows you to see past age. Love can be new and young again.”

Lauren Fleishman is a photographer currently based in London and a regular contributor to TIME. The Lovers is published by Schilt and is available here.

Paul Moakley is the deputy director of photography at TIME and you can follow him on twitter @paulmoakley

Contact us at letters@time.com.

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