From A Wiki of Ice and Fire
|Book||The Sworn Sword (appears)|
Wat was a farmer in service to House Osgrey during the reign of King Aerys I Targaryen.
The Sworn Sword
Wat was among those that were called by Ser Eustace Osgrey to defend the Osgrey lands after a disagreement over the Chequy Water with House Webber escalated into threats of war. He was sent home by Ser Duncan the Tall with the others when Duncan realized that it would be futile to fight.