Taylor Swift is said to have sworn off men before meeting Calvin Harris.

The 26-year-old singer recently celebrated her one-year anniversary with her DJ beau – the longest relationship the Shake It Off star has had in a long time.

She has previously been involved with stars including One Direction’s Harry Styles and actor Jake Gyllenhaal and it's thought the former romances caused her to consider taking a break from the world of dating.

However, when she met Calvin, Taylor apparently knew she had to give things a go.

“Before meeting Calvin she'd completely sworn off men and was focusing on her career,” an insider told Britain’s Grazia magazine. “The last thing she wanted was to get involved with another high-profile man but they just clicked.

“This is the most secure Taylor has ever felt. It's not been easy getting there after everything she's been through with her previous boyfriends but Calvin has proved over the last year that he's The One.”

Calvin spending Christmas (Dec15) with Taylor’s family in Colorado “sealed the deal” for both the stars, the source added. The couple have recently enjoyed some time alone together when they jetted to a tropical location for a much-deserved break.

Now the pair’s pals are gearing up for an engagement announcement, with the general feeling that Taylor and Calvin will undoubtedly be walking down the aisle at some point in the future.

“It definitely feels like that's where it's headed, but who knows how they'd find the time to plan a wedding,” the source smiled. “They had to move mountains to make their holiday work and their hectic schedules are a challenging obstacle when it comes to finding time for each other. But for now, as far as friends are concerned it's not a case of if, but when.”