Yoren was a recruiter for the Night's Watch.
Yoren is a sworn brother of the Night's Watch, in which he serves as a recruiter. He was forced to join the Watch after murdering the killer of his brother with an axe. Yoren's job is to travel the Seven Kingdoms searching for fresh recruits, either volunteers or criminals that choose a lifetime on the Wall over punishments such as death or mutilation.
Yoren meets Jon Snow, Tyrion Lannister, and Benjen Stark as they are traveling north to the wall. He arrives at their camp with two rapers, one of which is Rast.
Tyrion Lannister befriends Yoren at Castle Black, enjoying the fact that the brother of the Night's Watch has a sense of humor, unlike most of his comrades. They talk about what the strangest thing they've ever eaten is; Tyrion asks if Dornish women count. Yoren considers Benjen Stark as a close friend and ally and sees him off when he departs on a ranging beyond the Wall. He agrees to travel with Tyrion on the Kingsroad back to King's Landing to pick up more recruits from the city dungeons. He is present when Commander Mormont asks Tyrion to use his connections to intercede on behalf of the Night's Watch for more and better quality recruits and funds to rebuild
Yoren and Tyrion arrive at Winterfell, and Robb says pointedly that any man of the Night's Watch is welcome as a guest (making it clear that Tyrion is not welcome). After Tyrion gives Bran the plans for a new saddle Robb changes his mind, but Tyrion says he would prefer the brothel in town. On the road south, he is still travelling with Tyrion when they reach the Crossroads Inn, where he witnesses Tyrion being taken into custody by Catelyn Stark. Yoren rides with all speed to the Red Keep, where he finds Ned Stark and is introduced to Arya (after first mistaking her for a boy). After Jory takes Arya from the room Yoren is able to warn Eddard Stark about his wife's actions before they become public. Eddard agrees to let Yoren comb the city dungeons for fresh recruits for the watch.When Eddard is confronted with his wife's actions he then takes the blame, saying she acted on his orders, leading to confrontations with Robert Baratheon and Jaime Lannister.
Eddard is arrested for treason when he questions the legitimacy of the king's successor, Joffrey Baratheon. Lord Stark is brought to the Great Sept of Baelor to stand trial and Arya watches from the square. To see over the heads of the crowd, she climbs onto the pedestal of Baelor's statue. When Eddard is brought out he spots her. Then as Eddard is pulled through the crowd, he goes past Yoren and manages to point her out to Yoren by head jerk and saying "Baelor" hoping that Yoren will recognize her and wishing him to protect Arya. Despite a confession, Eddard is unexpectedly executed on Joffrey's orders.
Yoren grabs Arya as she is trying to rush to her father. She is pushing her way through the crowd trying to draw her sword. He holds her still, covers her ears, and keeps her from witnessing the beheading by blocking her view. Once out of the square he cuts Arya's hair with a knife and instructs her to pose as a boy. He intends to take her north to Winterfell and safety, hiding her among a group of 20 recruits for the Night's Watch. He instructs her to go by the name Arry the orphan boy, because no one cares or asks questions of orphans. Yoren warns her not to trust the other recruits, as any of them could turn her in for a reward, or rape her.
Yoren takes the recruits along the Kingsroad into the Riverlands. He warns the rest of the party to stay away from the three prisoners caged in the wagon. Two gold cloaks find the party camped in the Riverlands. The lead gold cloak calls to Yoren, asking if he is in command of the group. Yoren ignores the question and tells them that they are a long way from home. He walks across a wooden bridge towards the visitors. The gold cloak reminds Yoren that he asked a question and Yoren says that he asked without manners so he chose not to answer. Yoren grips the blanket that protects the gold cloaks horse from the saddle. The gold cloak produces a scroll and says that it is a royal warrant for one of Yoren's “gutter rats”. Yoren says that the recruits belong to the Night's Watch and are beyond the reach of kings and queens. The gold cloak moves to draw his sword but is halted when Yoren places the point of his dagger against his femoral artery. Yoren notes that men worry about their throats but often forget about the vulnerability of their lower regions. He tells the gold cloak that he has sharpened the knife and warns him that no-one can save him if the artery is nicked. Yoren takes the man's sword, saying that good steel is always needed on the wall. The recruits have surrounded the gold cloaks, weapons in hand. One of them picks up the sword from the ground. Yoren tells the gold cloak that he has a choice; die there or return to King's Landing and tell his master that they did not find what they were looking for. The gold cloak defiantly shouts that they are looking for Gendry and describes the bull's head helmet that he carries. He offers a reward to anyone turning him over and promises that he will return with more men. He warns Yoren that he will take his head home along with the “bastard boy”.
Arya sits up cleaning Needle while the rest of the recruits sleep. Yoren enters and sits across from her. He notices her watching him and asks what she wants. She asks him how he sleeps with the terrible things that he has seen. He says that he prevented her from seeing her father's execution. She says that she cannot forget seeing the Queen, Joffrey and Sansa standing next to him on the podium. He tells her about the murder of his brother by a boy named Willem. He says that he thought constantly about revenge and eventually made it a ritual to say the killer's name before falling asleep. When Willem returned to town Yoren killed him with an axe and then took his horse to ride to the Wall and join the Night's Watch to avoid prosecution. He urges Arya to get some sleep but they are interrupted by horns sounding outside. Yoren wakes his recruits and marshals them for a fight. He warns Arya and Gendry to stay out of sight and flee north if the fight is lost. Lommy picks up Gendry's bull helm. As they rush outside one man trips and drops his torch, setting a fire near the prisoner wagon.
They are met by Ser Amory Lorch and a force of men loyal to House Lannister. Lorch points out the Gold Cloaks with him and says that they have come for Gendry. Lorch orders Yoren and the recruits to drop their weapons. Yoren remains defiant and Lorch orders him shot. Yoren takes a quarrel to the shoulder but kills the crossbowman before he can reload. Yoren fights alone, killing several men before he is overwhelmed. Lorch himself kills Yoren by driving his sword through the back of his neck.
The Night's Watch recruiter who traveled the kingdom in search of new brothers to bring back to the Wall, Yoren spirited Arya Stark away from King's Landing after her father's execution. He died at the hands of Lannister men during his journey to return Arya to Winterfell.