Ser Benfred "Blackheart" Tanner, self-styled Lord Blackwater of Stokeworth, is a hedge knight and sellsword who became the Sergeant at Arms for the Red Keep.
Ser Benfred Tanner claims descent from the noble house Blackwater, formerly Lords of Stokeworth, but records show that the house that briefly ruled that castle some 200 years previous lasted only two generations, before being legally ousted by the current holders, House Stokely, was never called anything but Tanner. Benfred's father, Abelar Tanner, was killed when Benfred was five-and-ten in a fight with several Stokely men-at-arms, but before his death he managed to raise his son as a warrior of some skill and little honor. He also instilled in his son a sense of justice that leads Benfred to occasionally try to reclaim Stokeworth.
Benfred's mother runs an inn in the Crownlands.
Benfred fought and killed Jacen Stokely, the heir to Stokeworth, in the streets of King's Landing. As he fled the scene of the crime, he met Butterbumps the fool, who saved him from a squad of goldcloaks. They decided to join forces to infiltrate the Queen's feast, where Benfred claimed to be a Stokely knight.
He and Butterbumps managed to accidentally abduct Lord Ferment Redwyne, who was attempting to escape the city after his own failed attempt to poison the King and Queen was pinned on his brother. When Benfred and Butterbumps discovered the identity of their captive and learned that a reward was being offered for his capture, Ferment tried to flee.
Benfred brought the man's false hand to the capital, explaining that Redwyne had fallen a great distance, one he wouldn't likely be able to survive. He was rewarded with a mostly nominal position in the Red Keep as Sergeant at Arms, and Butterbumps was appointed the official court fool.
Damon Lannister enlisted Benfred's help in investigating a murder at a motherhouse named for Mellara Tyrell. Benfred suspected one of the girls of robbing the house, and sought to prove it to the skeptical King. A mishap in their search for the culprit led them to take shelter in a brothel. After learning of the visit, Queen Danae ordered Damon to return to the Westerlands and Benfred accompanied him out of concern for his own life, due to his involvement.
At the Tournament of the Three Ships in the Westerlands, Jeyne Estermont accused a peasant boy of abducting her youngest daughter, Katelyn. Benfred volunteered as the boy's champion in the subsequent trial by combat, losing an eye before managing to defeat Ser Gunthor Lannister. The nobility of the Westerlands dubbed him "Blackheart" afterwards.
Benfred traveled back to King's Landing with Damon Lannister, making it back to the Red Keep after a mishap on the way involving a group of bandits posing as mummers. Soon after, he went with the King on a journey through the Crownlands to investigate progress on and complaints regarding the roads project Damon had begun some time earlier. While there, Benfred led the King's scouts in an encounter with a rebellious knight's soldiers. The trip also included a visit to Harrenhal before the group returned to King's Landing.
"I am merely a humble scum-of-the-earth murderer."
“Do you know what most men would say is your defining trait, Benfred? Your lack of manners.” - Damon Lannister
“Gold doesn’t always breed loyalty. Nor does owing someone everything. Plenty of cutthroats turn their cloaks on gold or debt. Particularly for foolish things, like gods or lust or family.” - Benfred to Damon Lannister
"Did I ever tell you that you have my father’s name? He was the first person I went to when I killed my first man. I was thirteen, and he told me that it never gets easier. That was a lie too, though. It does get easier, if you’re not careful. I let it get easier." - Benfred to Abelar Greenfield
"Ryman still could not bring himself to trust the former sellsword. He was a reasonable blade, and clearly a friend to the King, but the old Knight had met many charming and friendly sellswords on many a field and they picked your teeth when you fell all the same, no matter how many ales you had shared with them that evening." - Ryman Sunglass
"The second man was hunted down by the infamous Ser Benfred Blackheart, who killed him so brutally that his remains were unidentifiable. I heard he ripped Lord Redwyne straight to pieces. I heard it’s like a sport for him, killing.” - Meredyth Tyrell
"...[B]lackhearted vagabond... A common miscreant. An upjumped, one-eyed pickpocket." - Jeyne Lannister
"Lyman loathed the capricious, self-aggrandizing man. He was without, it seemed, a single code or scruple to speak of, a treacherous, traitorous, dangerous narcissist with all the self-control of a rabid dog and an epically inflated opinion of his own self-worth. In short, he was everything Lyman was not… yet they all loved him for it. The King in particular seemed to have a peculiar affection for the man. They’d laughed and talked the whole ride up." - thoughts of Lyman
"The criminal called Benfred Blackheart remains the single greatest disgrace to knighthood that this realm has yet to witness... Perhaps the greatest source of corruption for the King." - the Golden Spurs
“Isn’t he the man who fought Ser Gunthor Lannister? Then I’d say he’s probably fairly good with a sword.” - Jason Frey
"[T]he Spurs won’t be appeased so long as you keep Blackheart at your side. The man is a rogue. A loyal rogue, I’ll give you, but a rogue all the same.” - Harrold Westerling
"Ser Benfred had such a look in his eye when he stood next to the King, one that was like a great beast ready to strike any who would try to harm his liege." - thoughts of Elena Crakehall