The two have indeed shared a lot of milestones together, which includes getting matching tattoos. Turner revealed to Elle UK that they decided to get the tattoo in September last year to commemorate the day they secured their roles for the global hit drama.

"We always said that we wanted them so we got the date 07.08.09 on our arms because that's the date that both of us found out we'd got our roles in 'Game of Thrones,'" the 21-year-old actress said.

They had their tattoos done in Belfast, Northern Ireland when they got a day off from filming. This was announced by tattoo artist Kat Paine on her Instagram account.

Although the two actresses have shown an inseparable bond in the outside world, they have actually spent most of their time apart in the "Game of Thrones" series. The on-screen Stark sisters have been separated since the season 1 finale after their father Eddard "Ned" Stark (Sean Bean) was executed by beheading in front of his two daughters.

After that, the two sisters spent some years apart fighting their own battles. They only got to reunite earlier this year in the fourth episode of season 7, "Spoils of War." That season ended with another execution, but this time the two sisters were united on the winning side.

No confirmed date yet on when "Game of Thrones" will return for its eighth and last season.