From A Wiki of Ice and Fire
|Book(s)||A Storm of Swords (Appears)|
Thirty years before the War of the Five Kings, Ser Wynton came within a dozen votes of being named Lord Commander. He has been a ranger in the Night's Watch for eighty years. His mental state has significantly deteriorated within the last ten years.
A Storm of Swords
Ser Wynton was among those left behind at Castle Black when Lord Commander Jeor Mormont went beyond the Wall in search of Benjen Stark and Mance Rayder. He was made castellan of Castle Black by Bowen Marsh when Marsh went off to investigate reports of wildling incursions, on account of being the only knight to remain stationed there.