Game of Throwbacks!
In the photograph, both Madden and Harington, 32 (who play Jon Snow and Robb Stark on the show, respectively) smile for the camera, while Allen, 32, (who plays Theon Greyjoy) hams it up in a gray hoodie and keeps his eyes and mouth open wide.
“#TBT This is Kit, Alfie and I after our first read through of S1 Ep1 of Game of Thrones about 10 years ago. KIDZ,” Madden captioned the sweet shot.
The pals appeared to have had fit in a visit to the iconic Northern Ireland Ferris wheel, The Wheel of Belfast, between GOT rehearsals.
The trio starred on the long-running HBO drama together for several years. While Madden’s character has since been killed off, Harington and Allen are still currently featured in the series’ final season.
Over the years, their friendships have also extended beyond the screen, leading the costars to support one another in their other ventures, such as when Madden and Harington attended the press night of their faux little sister’s, actress Maisie Williams, new play, I and You last October.
PEOPLE recently unearthed an early photo featuring a few of the youngest cast members at one of their first public outings together — a 2009 book event for Thrones author George R. R. Martin — and some of the actors were both delighted and horrified to see it.
“I remember this day very distinctly,” Harington told PEOPLE. “It was in Belfast and we went along to a book signing that George was having. This is the first time I ever really posed for a photo, and it was really bizarre because this is right at the beginning, none of us know what’s going to happen at this point.”
Harington’s onscreen sisters Sophie Turner (Sansa Stark), 23, and Williams (Arya Stark), 21, weren’t quite as happily nostalgic about the photo.
“Okay, two of these five people are prepubescent,” noted Williams. “Why do five of five people look prepubescent?”
Added Turner: “Prepubescent, that’s so true. It looks like a bunch of inbred cousins.”
“Oh God, it’s just awful,” agreed Williams. “It does like [they’re] going to their first-ever book shop.”
“Everyone just looks so weird!” said Turner.
Harington, however, admitted that one thing still hasn’t changed from 2009 to now. “I still pull that face in every photo shoot,” he joked.
GOT‘s season 8 premiere last week became the most-watched entertainment program of the year, bringing in 17.4 million viewers across multiple platforms, Entertainment Weekly reported. The show also became HBO’s largest telecast in its 46-year history.
Game of Thrones airs Sundays at 9 p.m. ET on HBO.