Edmure is the son and heir of the late Lord Hoster Tully of Riverrun. He is the younger brother of Catelyn and Lysa.
Ser Edmure is the son and heir of Lord Hoster Tully. Edmure is the new head of House Tully and thus has recently become the Lord of Riverrun and Lord Paramount of the Riverlands. The Riverlands are one of the constituent regions of the Seven Kingdoms and House Tully is one of the Great Houses of the realm. Riverrun is the ancestral seat of House Tully.
Edmure's mother Minisa Tully died in childbirth during his early childhood. He has two elder sisters Catelyn and Lysa. He was also raised with his father's ward, Petyr Baelish. It was Edmure who first nicknamed him "Littlefinger."
Catelyn is the widow of the late Eddard Stark, Lord of Winterfell and Lord Paramount of the North and Lysa is the widow of Jon Arryn, Lord of the Eyrie and Lord Paramount of the Vale.
Edmure presides over the funeral of his father, per the custom of House Tully, in which the departed is placed on a funeral boat and set on flames with a flaming arrow. Edmure fails at hitting the boat, causing his annoyed uncle to push him away and complete the deed himself. Later he's chided by King Robb and Ser Brynden for attacking Stone Mill, an attack in which more than two hundred men were lost only for Ser Gregor Clegane to flee south to Casterly Rock and only two unimportant nephews of Tywin Lannister to be taken hostage.
When emissaries from House Frey arrive at Riverrun to negotiate Walder Frey's terms of reconciliation with Robb Stark, Edmure is pressured by Robb, Brynden and Catelyn to take Robb's place in his previously arranged marriage to Roslin Frey as compensation for his military blunder at Stone Mill. Edmure reluctantly agrees.
En route to the Twins for Edmure's wedding, the Stark and Tully army is forced to make camp due to heavy rain. Catelyn and Brynden warn that Walder Frey is a prickly man and will take the delay as another slight.
Upon finally arriving at the Twins, Edmure nervously eyes Walder Frey's brood, trying to figure out which of the unattractive bunch is to be his wife. At the ceremony, Walder lifts Roslin's veil, revealing her to be a beauty, much to Edmure's relief, Robb's shock, and Catelyn, Blackfish and Walder's amusement. At the wedding feast, Edmure enjoys himself immensely, when Walder and Robb call for the bedding ceremony, eagerly allows himself to be led away by the other Frey girls. It is only after his departure that the Red Wedding begins.
Edmure is taken prisoner and remains a hostage of Lord Frey.
Edmure is still a captive at the Twins when Ser Brynden raises what remains of the Tully army and retakes Riverrun. When Walder learns of this, he summons Edmure into his hall, and orders Lothar Frey and Walder Rivers to use him in taking back Riverrun.
While the Freys are sieging Riverrun, outside the castle, Edmure stands beside Lothar Frey and Walder Rivers with a noose around his neck. They threaten to hang him if the Blackfish doesn't surrender Riverrun, but the Blackfish says nothing. When they hold a knife to Edmure's throat and threaten to cut his throat, the Blackfish calls their bluff and dares them to, knowing that if Edmure dies, the only chance the Freys have of taking the castle is by attacking it. Shortly thereafter, Ser Jaime Lannister arrives with a Lannister host to take command of the siege from the Freys. He chastises the Freys for not being prepared to carry out their threats and orders Black Walder to bathe and feed Edmure.
Later, Jaime meets Edmure in the tent where he is being imprisoned and implores him to appeal to his uncle to surrender Riverrun. Jaime offers to reunite him with his wife and son and have him live out his days as a hostage at Casterly Rock. His son will be tutored, trained in combat, and given his own keep when he comes of age. Jaime threatens Edmure with his son's death when Edmure refuses, and Edmure reluctantly complies.
Edmure approaches Riverrun's gates and requests entry as the Lord of Riverrun and head of House Tully. The Blackfish orders his men not to let him in, as he knows that Edmure is coming to demand the surrender of the Tully garrison. Sworn to the head of House Tully and not the Blackfish, the Blackfish's men see no option but to comply with their lord's demand, and allow Edmure entry. Upon entering, Edmure demands that his men surrender, that the gates be lowered to allow in the combined Lannister and Frey force retaking the castle, and that his uncle be captured. The Lannister-Frey army enters Riverrun, but as Jaime had hoped, it is a peaceful surrender and no lives are lost. A Lannister guard later reports to Jaime, however, that the Blackfish died fighting when the guards came to restrain him.
Walder Frey later mentions that Edmure is back in a cell, although he has no plans to kill him as "killing [his] son by law would not be right." After the celebration, however, Walder is murdered by Edmure's niece Arya Stark.
Younger brother of Catelyn Stark and Lysa Arryn, Edmure fought on Robb Stark's behalf throughout the Riverlands. Although well-intentioned, he lacks the military instincts of his father and uncle. As part of a bargain made with walder Frey, Edmure married Walder's daughter Roslin, the violence that ensued that day obliterated the Stark army and became known as the Red Wedding. Unharmed, Edmure was held hostage by his in-laws until Jaime Lannister traded Edmure's release for the surrender of Riverrun of the Freys. The Freys took Riverrun and re-confined Edmure to a cell.