Greenshield is one of the Shield Islands in the Reach. The northernmost of the isles, it lies near the mouth of the river Mander. It is the seat of House Chester.
In 89 AC, Princess Rhaenys Targaryen informed her grandfather, King Jaehaerys I Targaryen, her intention to marry Lord Corlys Velaryon while the two were in Lord Chester's hall on Greenshield.
Greenshield is conquered by the ironborn during the Battle of the Shield Islands. After the battle, King Euron Greyjoy raises Lord Maron Volmark to its lordship.