House Grimm of Greyshield rules the island Greyshield, one of the Shield Islands of the Reach, from their castle, Grimston.
Neither their arms nor their words appear in the books, but according to semi-canon sources they blazon their shield as an iron escutcheon with silver studs on a grey-green field strewn with longships proper.
During the Dance of the Dragons, Lord Grimm declared Greyshield for the blacks.
Game of Thrones is roughly based on the storylines of A Song of Ice and Fire, set in the fictional Seven Kingdoms of Westeros and the continent of Essos. The series chronicles the violent dynastic struggles among the realm's noble families for the Iron Throne, while other families fight for independence from it. It opens with additional threats in the icy North and Essos in the east. Dive deep in the big world of Westeros or Essos.With us, you will learn all the history and geography about all houses castles and much more.