River Mersey

The River Mersey is a major waterway in north-west England; the city of Liverpool lies on the north bank of its estuary where the river flows into the Irish Sea. Traitionally the river has formed a political boundary, and this is reflected in its name, which derives from the Old English Maeres-ea, 'boundary river'. In Anglo Saxon England the Mersey was the boundary between the kingdoms of Northumbria and Mercia; later, it formed the boundary between the counties of Lancashire and Cheshire. Only in 1974 did it cease to be an important boundary marker, with the creation of new counties spanning the river, and the alteration of other boundaries.