In the photo, the couple attends the premiere of HBO's 'Game Of Thrones' season 7 at Walt Disney Concert Hall on July 12, 2017 in Los Angeles, California.
The announcement in the 'forthcoming marriages' sections reads: "Mr K.C. Harington and Miss R.E. Leslie - The engagement is announced between Kit, younger son of David and Deborah Harington of Worcestershire, and Rose, middle daughter of Sebastian and Candy Leslie of Aberdeenshire".
Harington, 30, plays Jon Snow on the globally popular hit fantasy series, while Scottish-born Leslie, 30, played his wildling love interest Ygritte on the HBO show before leaving in 2014.
People reports that Harington and Leslie are engaged after five years of dating.
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"Kit's known for ages he's wanted to marry Rose but he wanted them to get a house and settle down a bit first", the source added.
After keeping their romance under wraps for four years, the couple appeared in public together last year and they also reportedly moved into a £1.75million mansion in East Anglia in January 2017. Now though, it looks like they are taking things even further. "The three weeks in Iceland when we were shooting the second season", he said.
We're thinking tables named after different houses (Baratheon, Stark, Lannister, Targaryen, Tyrell, Greyjoy) or locations (Winterfell, Dragonstone, King's Landing, Dorne, The Wall) - and an Iron Throne 'for two' at the top table for the bride and groom. "Always. There will be no one else".