"In 1740, the uninclosed lands on the North side of the River, denominated Sealand, amounted to 4,818 acres."
[From A Memoir of Hawarden Parish, Richard Willett, 1822]
During the eighteenth century, in an attempt to assist navigation to Chester, the River Dee to the west of Chester was diverted into a man-made channel, some distance south of its former course. The Flintshire/Cheshire border still follows the former line of the river. An extensive area of marshland, within the parish of Hawarden, but to the north of the new channel, was reclaimed as a result of this diversion. This reclaimed area became known as Sealand.