Back in July, "Sherlock" co-creator and actor Mark Gatiss announced he would be joining the cast of HBO's hit show "Game of Thrones" for its fourth season, and following months of speculation from fans, Gatiss's role has now been revealed, WinterIsComing.net reports.

Gatiss's official CV reveals that he will play Tycho Nestoris, a banker and representative of the Iron Bank of Braavos who is sent to the Wall to, later on in the story, negotiate payment of the debt of the Iron Throne with a very important main player.

The Iron Bank of Braavos is known in the Realm for always collecting their debts, much as the Lannisters are known for always paying theirs. In season 3, newly crowned Master of Coin, Tyrion Lannister, warns that those who fail to repay the Iron Bank will watch as their enemies are funded by them. And the Crown, he cautions, is already heavy into debt with the bank.

In the source material "A Song of Ice and Fire," Tycho Nestoris is described as a tall, gaunt man with long legs and a thin beard. WinterIsComing.net's consensus is that Gatiss is a good match for the role, as he has a "knack for dryness, snark, and intelligence [that] will suit the part perfectly."

Fans speculate that the character will come into play a little earlier on than he does in the books, as he is first introduced in "A Dance With Dragons," while season 4 of "Game of Thrones" covers the second half of "A Storm of Swords."

So far, Pedro Pascal (Oberyn Materll), Roger Ashton-Griffiths (Mace Tyrell), Indira Varma (Ellaria Sand, Oberyn's lover), Joseph Gatt (Styr, Magnar of Thenn), Elizabeth Webster (Walda Frey), Lu Corfield (Mole Town bordello owner) and Hoji Fortuna (role as yet unknown) have all been confirmed as new actors joining the cast for season 4, as the show continues to expand its ever-evolving, long list of characters.

Sept. 7 marked day 52 of filming for "Game of Thrones," members of the cast shooting on location at the Walls of Dubrovnik in Croatia.

Click here to see photos from day 52 of filming.