The original giant lake can be seen on Christopher Saxton's map from 1579 and stretched from Rufford in the east, to Churchtown (then known as North Meols) in the west.

Active management of the mere began in 1692 when Thomas Fleetwood of Bank Hall cut a channel in an attempt to drain it.

"The newly formed valleys of the Mersey, Ribble, Dee, and Lake District rivers likely created a large delta in the Irish Sea, around 50 miles (80km) west of the current coastline.

Around 12,000 years ago, sea levels were approximately 164 feet (50km) lower than today, and the entire Lancashire plain, along with the land to its west, was a freshwater landscape of rivers, streams and lakes".

[6] These lakes formed in depressions within the boulder clay, and one of these, south of the Ribble, gradually developed into the early Martin Mere.