Mark Stanley

Mark Stanley (born 29 April 1988 in England) is an English actor best known for playing the role of Grenn in the HBO series Game of Thrones (2011-14). He appears briefly in the film Star Wars: The Force Awakens (2015) as a member of the Knights of Ren.

I met Mark at Film & Comic Con Newcastle in March 2015.

Links:
IMDb
Wikipedia