King Renly Baratheon's camp is a hive of activity as his troops prepare for the coming battle with the forces of King Stannis Baratheon in darkness. The camp is beset by strong winds. Catelyn Stark meets with King Renly in his command tent. Ser Robar and his sworn, Ser Emmon Cuy, are outside while Brienne of Tarth stands watch inside the tent. Hearing Brienne scream the guards rush into the tent with swords in hand. They see Brienne kneeling over Renly’s corpse and assume that she is responsible. They threaten her life. Catelyn tries to intervene but they push her aside. Brienne fights both of them off, killing them.
In the Song of Ice and Fire novels, Ser Robar Royce is a member of Renly's Rainbowguard as Robar the Red, the second son of Lord Yohn Royce of Runestone and older brother of Ser Waymar Royce of the Night's Watch. He had joined Renly seeking the glory he would never find as the second son of a noble house. Ser Robar Royce and Ser Emmon Cuy arrive just after Renly's assassination. Cuy blames Brienne for the death and attacks her. Catelyn Stark convinces Robar that Brienne is innocent and he fights off the men-at-arms that follow Cuy. Ser Robar is later killed in a fit of rage by his Lord Commander, Ser Loras Tyrell.