Ser Leslyn Haigh is married to Perianne Frey, Walder Frey's only daughter from his first marriage to Perra Royce. Leslyn has three sons, Ser Harys, Ser Donnel and Alyn, and through Harys a grandson, Walder Haigh.

Before the Red Wedding Ser Leslyn Haigh is introduced to Catelyn Stark. When the massacre starts he attacks Lord Jon Umber "the Greatjon". Merrett Frey, Petyr Frey and Whalen Frey have tried to make the Greatjon too drunk to fight. However the Greatjon snatches a sword from the first man to attack him, breaking their arm. It takes eight men to put him in chains, and he kills one, wounds two, and bites of half of Leslyn Haigh's ear.