The hit HBO series, 'Game of Thrones', is expected to premiere its Season 5 sometime in April, 2015. The popular television fantasy drama is based off the novels of George R.R Martin, who's in the midst of completing his upcoming 'Winds of Winter' novel.

Considering the cast in the upcoming season of 'Game of Thrones' fans should expect to see some major changes. For one, Tywin Lannister, will not be appearing in the season, as he was killed off the finale episode of Season 4, by his own son, Tyrion Lannister.

Fans should not expect to see the character in the upcoming installment, especially since the series does not focus on a flashback element in any way shape or form.

Beyond that, fans should not expect to see Kristian Nairn (Hodor) or Isaac Hempstead-Wright (Bran Stark) in Season 5 either. Their storylines, based off George R.R Martin's novel series 'A Song of Ice and Fire', are up to date in the series.

Evidently, 'Game of Thrones' is going to focus on the other characters all over the realm of Westeros.

In terms of new addtions to the cast, it has been confirmed that Alexander Siddig will be playing the role of Doran Martell, Oberyn Martell's older brother and the ruler of Dorne. Fans can recall that Oberyn was killed in a fight to the death against The Mountain, as he tried to seek justice for Tyrion Lannister who was condemned to death.

The producers have also added Rosabell Laurenti Sanders as the character of Tyene Sand, Keisha Castle in the role of Obara Sand, and Jesica Henwick as Nym Sand. These three women will play the roles of Oberyn's illegitimate daughters.

Jonathan Price was also added to the cast of Season 5, he will play the role of high sparrow, a religious leader. Aimee Richardson who had played the role of Myrcella, Cersei's daughter in the previous season will replaced by Nell Tiger Free.

While the series is based on the novel series, 'A Song of Ice and Fire' as a whole, this installment will mostly stem from the fourth and fifth novels, 'A Feast for Crows' and A Dance with Dragons'.