Eustace Osgrey

Ser Eustace Osgrey was a landed knight of Standfast.

Background
Ser Duncan fought for him against the champion of the Red Widow of Coldmoat, Lucas Longinch during a trial by combat.

Season 8
Esutace is mentioned as "Red Widow of Coldmoat" under Ser Duncan the Tall's entry, in The Book of Brothers, which the new Lord Commander of the Kingsguard Brienne of Tarth flicks through.