In the 16th century, the hilltop monastery became a Franciscan friary supported by the Flemings. In the grounds of Slane Castle are the ruins of St. Erc's Hermitage. This consists of a late fifteenth or early sixteenth century chapel and an earlier dwelling. The 12th century martyrology of Gorman called him: Erc of Slane, bishop of Lilcach and from Ferta Fer Feic beside Sid Truim from the West (Ferta Fear Fiac means the Graves of the Men of Fiac).