The Humberhead Levels cover a large expanse of very flat, low lying land towards the eastern end of the Humber

Humber

The Humber is a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal River Ouse and the tidal River Trent. From here to the North Sea, it forms part of the boundary between the East Riding of Yorkshire on the north bank...

 estuary in northern England. The Levels occupies the area of the former Glacial Lake Humber. The area bounded to the east by the Yorkshire Wolds

Yorkshire Wolds

The Yorkshire Wolds are low hills in the counties of East Riding of Yorkshire and North Yorkshire in northeastern England. The name also applies to the district in which the hills lie....

 and the northern Lincolnshire

Lincolnshire

Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...

 Edge, a limestone escarpment

Escarpment

An escarpment is a steep slope or long cliff that occurs from erosion or faulting and separates two relatively level areas of differing elevations.-Description and variants:...

, and to the west by the southern part of the Yorkshire magnesian limestone

Dolostone

Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite. In old U.S.G.S. publications it was referred to as magnesian limestone. Most dolostone formed as a magnesium replacement of limestone or lime mud prior to lithification. It is...

 ridge. In the north the Levels merge with the slightly more undulating Vale of York

Vale of York

The Vale of York is an area of flat land in the north-east of England. The vale is a major agricultural area and serves as the main north-south transport corridor for northern England....

 close to the Escrick glacial moraine, and to the south merge into the Trent

River Trent

The River Trent is one of the major rivers of England. Its source is in Staffordshire on the southern edge of Biddulph Moor. It flows through the Midlands until it joins the River Ouse at Trent Falls to form the Humber Estuary, which empties into the North Sea below Hull and Immingham.The Trent...

 Vale.

Glacial Lake Humber

During the last ice age, a glacier extended across this area almost to where Doncaster

Doncaster

Doncaster is a town in South Yorkshire, England, and the principal settlement of the Metropolitan Borough of Doncaster. The town is about from Sheffield and is popularly referred to as "Donny"...

 now is. The main glacial front was at Escrick where the Escrick moraine marks its furthest extension. This formed the northern limit of an extensive lake which was impounded by the blocking of the Humber gap by another ice front. The lake bottom was gradually filled with clay sediments, which are up to 20 metres thick in some places. These clay sediments are locally overlain by peat deposits forming raised mires. At the base of the peat layers can be found the remains of a buried forest.

Early settlement

The Humberhead levels have been settled for several thousand years. The drier northern area was settled before the Roman era. The lighter soils there were easier to drain with hand tools, and the area was extensively cleared for small-scale pastoral farming.
The system of easily navigable rivers was used by invading late fifth- and sixth-century Angles and eighth- and ninth-century Vikings to penetrate deep into the countryside.