Jon Connington is the only surviving son of Armond Connington, Lord of Griffin's Roost, and his wife. He served as a squire in King's Landing along with Prince Rhaegar Targaryen.
Due to his connections with the royal family, and because he was a noted warrior, Aerys II chose him as Hand of the King after the dismissal of Owen Merryweather. Aerys wanted someone young and vigorous to match the rebelling Robert Baratheon's youth and vigor. After the Battle of Ashford, Connington took over the pursuit of Robert Baratheon from the Tyrell army. In the Riverlands, near the town of Stoney Sept, he caught up with Robert who was hiding in the town. Connington's soldiers began a house-to-house search after failing to find him, Robert Baratheon's allies arrived at Stoney Sept to oust Connington and his forces.
The Battle of the Bells began. The rebel army under the joint command of Eddard Stark, Jon Arryn and Hoster Tully immediately began attacking the royal army. Connington fought back fiercely. He managed to escape and was able to retreat in good order.
King Aerys II held Connington responsible for this defeat and exiled him, stripping him of his lands, wealth and titles. While in exile Connington joined the Golden Company and served with them for several years.