Ormund claimed to lead The Reach in support of King Aegon II Targaryen, his kinsman, although not all the Lords of the Reach followed him. Ormund was almost defeated at the Battle on the Honeywine when he was surrounded by the forces of Lord Thaddeus Rowan and Tom Flowers on one side and Ser Alan Beesbury, Lord Alan Tarly and Lord Owen Costayne on the other bank of the river. When the battle seemed lost it was his squire, Prince Daeron Targaryen, who arrived on the back of Tessarion and secured a victory for the greens. It was Ormund who knighted Daeron, naming him Ser Daeron the Daring.
He then marched up the Mander, defeating all the black armies that opposed him, before reaching the city of Tumbleton. He engaged the defenders of the town and the Winter Wolves charged his troops. The Northmen fought their way through his men and Lord Roderick killed Ser Bryndon Hightower when he stood between him and his liege lord, although Bryndon did take Roderick's shield arm. Despite these injuries Roderick still managed to defeat and kill Lord Ormund.