The Holy Island of Lindisfarne, commonly known as either Holy Island or Lindisfarne, is a tidal island off the northeast coast of England, which constitutes the civil parish of Holy Island in Northumberland. Holy Island has a recorded history from the 6th century AD; it was an important centre of Celtic Christianity under Saints Aidan of Lindisfarne, Cuthbert, Eadfrith of Lindisfarne and Eadberht of Lindisfarne. After the Viking invasions and the Norman conquest of England, a priory was reestablished. A small castle was built on the island in 1550.