Welsh actor Robert Pugh has been cast as the wildling who maintains an uneasy detente with the Night's Watch on the HBO drama.

HBO’s Game of Thrones has found its Craster in Robert Pugh.

The Welsh actor is joining the swelling cast of the Emmy-nominated HBO drama based on the George R.R. Martin novels as Craster, the tenuous ally to the Night’s Watch.

The master of Craster's Keep, which lies beyond the Wall, maintains an uneasy detente with the Night's Watch. For the HBO series, there's much about Craster to make Jon Snow (Kit Harington) uneasy -- including the fiercely unpleasant nature of his relationship with his 19 wives. But as Jon and Samwell (John Bradley) begin to dig deeper into the mysteries of Craster's Keep, they learn that this is only the tip of the iceberg.

Craster first appears in A Clash of Kings, the second book in the series. Hannah Murray was recently cast as Gilly, one of the women living with Old Craster who wants to escape his oppression.

STORY: ‘Friday Night Lights,’ ‘Game of Thrones’ Take Top Honors at TCA Awards

Pugh, whose credits include The Ghost Writers and Master and Commander: The Far Side of the World, is repped by Emptage Hallett in the U.K.

The series has been bulking up on casting, recently adding Roy Dotrice as Pyromancer Hallyne; German actor Tom Wlaschiha as Jaqen; and Gemma Whelan as Yara Greyjoy. Other additions include Stephen Dillane as Stannis Baratheon; and Carice van Houten as Melisandre.

Gwendoline Christie was also added as Brienne, Maid of Tarth, as was Natalie Dormer, who will play Margaery Tyrell.

Production on Season 2 of Game of Thrones is currently under way in Belfast.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit