James Faulkner
James Faulkner (left), pictured here with guest at Richmond Theatre on August 11, 2015, in Richmond, England, will portray Randyll Tarly on "Game of Thrones" Season 6. Getty

"Game of Thrones" has already depicted horrible fathers before with the way Tywin Lannister (Charles Dance) treated Tyrion (Peter Dinklage). But if you thought Tywin Lannister was a bad father, just wait until you get to see beloved hero Samwell "Sam" Tarly's (John Bradley) dad, Randyll Tarly, in "Game of Thrones" Season 6.

Randyll Tarly is going to be portrayed by actor James Faulkner ("Downton Abbey") in Season 6 of the HBO drama, according to Watchers on the Wall. Samantha Spiro ("London Spy") has also joined the cast as Sam's mother, Melessa Florent, as well as Rebecca Benson ("Shetland"), who will be portraying Sam’s sister, Talla.

Randyll is one of the most skilled warriors and leaders in all of Westeros, but Sam is overweight, smart and has no desire to fight. Sam went to the Wall when his father threatened him to join the Night's Watch and disinherit the family name or be killed. But what exactly is Randyll's deal, and what is his story in the "A Song of Ice and Fire" book series?

In the books, Randyll Tarly made a name for himself on the battle ground, as he was the only man to defeat Robert Baratheon during Robert's Rebellion. He is married to Melessa Florent, and is physically described as lean and balding with a short grey beard. Randyll is the Lord of Horn Hill and is also iron-willed, sharp and can be cold. Just as Jon Snow has a Valyrian steel sword in "Longclaw," Randyll also has a Valyrian steel blade called "Heartsbane," which could come in handy when the White Walkers finally come.

Aside from Sam, Randyll has another son, Dickon Tarly, who is the son that he always wanted who isn't afraid of battle. Dickon became the heir to House Tarly after Sam went to the Wall. In the “A Dance with Dragons” book, Dickon wed the daughter of the Lord of Maidenpool, Eleanor Mooton.

The Tarly's often team with House Tyrell, as Lord Mace Tyrell is his liege lord. Unlike on the show, Randyll has actually been involved in a few of the major moments before Season 6. He fought alongside the Lannisters in the Battle of Blackwater in the "A Clash of Kings" book, where they defeated Stannis Baratheon. Randyll has also crossed paths with Brienne of Tarth, which hasn't yet happened on the show. Brienne (Gwendoline Christie) was last seen in the Season 5 finale, appearing to finally get her revenge on Stannis (Stephen Dillane) for killing her lord, Renly Baratheon (Gethin Anthony).

Because of his house's loyalty to the Tyrell's, Randyll marches his army to King's Landing after learning that Margaery Tyrell was imprisoned in "A Feast For Crows." It will be interesting to see if this story plays out on the show, especially since he becomes a part of King Tommen Baratheon's small council after arriving in King's Landing in "A Dance For Dragons." There is also a very strong possibility that Randyll will come across Sam once again. We won't know for sure until "Game of Thrones," returns in 2016.