During the Second Siege of Riverrun, Jaime Lannister makes a deal with Edmure Tully: if Edmure surrenders Riverrun, Jaime will allow Edmure to live a comfortable life with his son and wife. Edmure capitulates, and orders his men to stand down and open the gates to the Frey and Lannister troops.
After the siege is resolved, Walder Frey hosts a feast for both the Freys and the Lannisters at the Twins to celebrate, where he reveals that he has had Edmure re-imprisoned; the whereabouts and status of Edmure's son is left unsaid, although it is presumed that he is safe with his mother.
and numerous mistresses
Walder's 8th wife
Walder's 9th wife
|"Lame Lothar" Frey|
|Edmure Tully||Roslin Frey||"Black Walder" Rivers|
|Roose Bolton |
|"Fat Walda" Frey|
|Newborn Bolton |
In the books
In A Song of Ice and Fire novels, Edmure did impregnate Roslin on their wedding night in the third book, but less than nine months pass by the time Jaime confronts the captive Edmure at the second siege of Riverrun in the fourth book, so Roslin is still pregnant when last seen. The TV series pushed back the Riverrun subplot, so more time has passed between the Red Wedding (at the end of Season 3) and when Jaime confronts the captive Edmure (in Season 6) - and thus enough time had to have passed for Roslin to give birth to the child (particularly due to the timing of Walda Bolton's pregnancy, given that it was a more important plot point that she married Roose after the Red Wedding but had time to give birth to a son by Season 6).
Because Edmure's child with Roslin hasn't been born yet its name is unknown. For that matter it is unconfirmed if it will be a boy or girl, though the TV series went ahead to say it is a boy (it is unclear if this is based on information Martin gave them).
In the books, Perwyn says that Roslin has been praying that her child will be a girl, fearing that if she gives birth to a boy her father will have no more need of her husband. Edmure knows about his wife's pregnancy, but is unaware that if the child turns out to be a boy, the Freys will dispose of him. Jaime promises Edmure, among his other terms of surrender, that he will send Roslin to join him in Casterly Rock under gentle imprisonment befitting a lord of his status; if her child is a boy, he will serve House Lannister as a page and a squire, and when he earns his knighthood they'll bestow some lands upon him; if Roslin gives birth to a daughter, Jaime will see her well dowered when she’s old enough to wed.
Jaime threatens Edmure that if he does not convince Riverrun to surrender, as soon as Roslin gives birth he will deliver Edmure's newborn child to the castle by firing it at the walls using a trebuchet. In the TV version Jaime threatened to do this with "a catapult" - a trebuchet is a bigger kind of catapult, though apparently the line was changed in case some viewers didn't know what a "trebuchet" was (the effect on the line is negligible). In the novels, this chapter is told from Jaime's inner POV narration, making it clear that this was actually an empty threat and he would never kill a baby - but he knows his enemies think of him as the honorless "Kingslayer" who would stoop to anything, so he decides to play up that false reputation to convince Edmure he isn't bluffing, when in fact he is. This isn't as clear in the TV version without Jaime's POV thought narration, however, in the behind the scenes video for that episode, Nikolaj Caster-Waldau (Jaime) indeed makes it clear that TV-Jaime was bluffing and wouldn't have actually killed Edmure's baby.
|Lord:||Edmure Tully||Heir:||Unidentified son|
|Title(s):||Lord Paramount of the Riverlands · Lord of Riverrun|
|Current members:||Roslin Tully|
|Deceased members:||Catelyn Stark · Hoster Tully · Minisa Tully · Lysa Arryn · Brynden Tully|