"Game of Thrones" season 4 promo photos are here! Check out all the recent sneak peek photos from HBO's "Game of Thrones," featuring Daenerys Targaryen, Sansa Stark, Jon Snow, Joffrey, and more in season 4!

One of the biggest things "Game of Thrones" fans will notice in the photo gallery above is the re-casting of Daario Naharis, as well as the introduction of new characters Oberyn Martell and Ellaria Sand.

In last August, HBO announced that "Treme" actor Michiel Huisman was joining the "Game of Thrones" cast, and would replace Ed Skrein as Daario Naharis, the love interest of Daenerys Targaryen, in season 4. It has not been announced why Skrein will no longer play Daario Naharis, but the casting choice for his character was met with mixed reviews from fans of George R.R. Martin's "A Song of Ice and Fire."

However, IB Times reports that this was mostly due to costume changes from the books than Skrein's acting skills: Daario first appears in "A Storm of Swords" with his hair and beard dyed blue and gold.

The photos above also show the first close up pictures of Pedro Pascal as Prince Oberyn, the Red Viper of Dorne, and Indira Varma as Ellaria Sand, the prince's companion.

"We finally introduce one of the most popular characters from the books: Prince Oberon Martell," George R.R. Martin told E! News in July. "The Red Viper of Dorne will be introduced for the first time and there will be some other new characters that I think the fans will like."

Meanwhile, HBO will air "Game of Thrones Ice and Fire: A Foreshadowing," which will be a 15-minute preview trailer for "Game of Thrones" season 4. The preview trailer has a release date of Feb. 9 at 8:45 p.m. ET/PT.

"Game of Thrones" season 4 premieres April 6 at 9PM on HBO.