Ser Eustace Osgrey was a landed knight and the Lord of Standfast.
In the books
In the Tales of Dunk & Egg, Ser Eustace is the lord of Standfast. He was the father of Addam who was in romantic relationship with Rohanne Webber of Coldmoat who blamed Eustace for his death. He tries to make peace with Coldmoat after Ser Bennis killed a peasant of Coldmat damming Chequy Water. As the peasants under his command were too few to go to war, Eustace decided to fight House Webber himself along with Ser Duncan the Tall and Prince Aegon V. She accepted the proposal of a trial by combat, which Duncan won but was seriously injured. This led to them reconciling, falling in love and marrying.