Nicola de la Haye is remembered, rightly, as the woman who held Lincoln Castle through a number of sieges. But while researching her life for Lady of the Castle, I became fascinated by another battle being fought on her lands.

It was a battle against the sea.

And, rather unexpectedly, I discovered that Nicola and Gerard’s attempts to win that battle may also have helped create an enemy who would eventually bring an army to the gates of Lincoln Castle—and come close to having Gerard hanged for treason.

A county being built out of water

Much of Nicola’s land lay in southern Lincolnshire, including estates at Sutton and Lutton in what was then a very different landscape from the one we know today.

Large parts of the Lincolnshire fens were still marsh, saltmarsh and seasonally flooded ground. If you wanted more farmland, you could not simply clear a few trees and start ploughing.

First, you had to make the land.