AirLockAlpha.com

"Stargate: Atlantis" actor Jason Momoa is joining the cast of HBO’s fantasy pilot “Game of Thrones,” which officially starts production Saturday.

Momoa will play Khal Drogo, a fierce leader of a massive clan of mounted Dothraki warriors. He catches the eye of prince Viserys Targaryen (Harry Lloyd), who desperately offers Drogo a marriage with his sister Daenerys (Tamzin Merchant) in hopes of securing an alliance.

Principal photography begins the last week of October in Northern Ireland. Other filming locations reportedly include Scotland and Morocco; at least part of filming for Momoa will likely occur in Morocco, which reflects portions of the Dothraki continent.

“Game of Thrones” is based on author George R.R. Martin’s bestselling “A Song Of Ice And Fire” novels. It follows the tragic struggle between royal families to secure ultimate power of the vast lands of Westeros, where dangerous men and women embrace a perilous game of treachery to win the throne.

Momoa played the tough Satedan native Ronon Dex on "Atlantis" for five seasons on Syfy. He is expected to reprise his role in the upcoming Syfy movie "Stargate: Extinction," but based on what executive producer Brad Wright told Airlock Alpha earlier this month during a set visit of "Stargate: Universe," that project is on an indefinite hold because of economic constraints.

Isaac Hempstead-Wright was also confirmed by HBO to be joining the “Game of Thrones” cast in the role of Bran Stark, the young son of lord Eddard "Ned" Stark played by Sean Bean. Bean, of course, starred as Boromir in the Lord of the Rings trilogy.

Bran's role becomes increasingly important to the story as it progresses.

Stepping aboard one of the network's most buzzed-about projects, Momoa and Hempstead-Wright represent the last key parts needed for the large ensemble cast.

Previous noteworthy casting announcements have included Lena Headey ("Terminator: The Sarah Connor Chronicles," "300"), who will play queen Cersei Lannister; Peter Dinklage as her cunning dwarf brother Tyrion; Nikolaj Coster-Waldau ("New Amsterdam") as her twin, Jaime; Jennifer Ehle as Ned's wife Catelyn Stark; and Mark Addy as King Robert Baratheon.

Tom McCarthy, who directed 2003's "Station Agent" and 2007's "The Visitor," will helm the series.

David Benioff ("Troy," "The Kite Runner") and D.B. Weiss penned the script and serve as executive producers. Martin, Guymon Casady, Carolyn Strauss and Vincent Gerardis also hold executive producing duties.

“Game of Thrones” will span a novel’s worth of material per season if the pilot is picked up.

The novel won the 1997 Locus Award, and was nominated for both the 1997 World Fantasy Award and the 1998 Nebula Award. More awards followed for subsequent books in the series. Seven novels are planned, with the fourth volume, "A Feast For Crows," being the latest.