Coster-Waldau, meanwhile, shared four pictures of the duo goofing around.
“The best, sweetest most wonderful sister from another mother,” he wrote. “That was a fun decade.”
Headey also honored Nathalie Emmanuel, whose Missandei of Naath character she ordered beheaded, with this picture:
She shared this video from the set:
And with this image, she described playing Cersei as “fun, and bonkers.”