The spelling of the name of the river has varied over the centuries.
- In 1190, it was referred to as 'the water of Lin', and in the 14th century as 'La Leye'.
- In 1576, the cartographer Saxton seems to have been the first to introduce 'Lea' to map-makers.
- In the 18th century, it was not infrequently called the 'Ware River'.
The commonest spelling would seem to be 'Lee'.
The Lee rises at Marsh Farm near Luton and travels some 42 miles to its confluence with the Thames at Bow.
The River formed the traditional boundary between the counties of Essex and Middlesex and, earlier, the dividing line between territories controlled by Alfred of Wessex (Alfred the Great) and Guthrum, the Viking ruler of East Anglia ('The Danelaw') after Alfred took control of London between 878 and 890.
The lower reaches of the river have been adapted and largely canalised over the centuries for a variety purposes. Firstly, to drain the marshes for agriculture and grazing, then to improve navigation and serve the needs of mill owners. The rapid urbanisation and industrialisation of the 19th century led to further changes to the character of the river, followed by a series of flood relief measures in the early to mid-twentieth century.
De-industrialisation and the formation of the Lee Valley Regional Park in the late 20th century has resulted, at least in part, in a gradual process of reinstatement of the semi-natural setting of the river.
At least six meanders were removed to aid navigation and limit flooding. The three below Lea Bridge were opposite Hackney Marsh, including the 'Friends'. The three above Lea Bridge were north of Essex Wharf, the confluence of the Coppermill Stream with the Lea (Springfield Marina) and a meander just to the north of this (now under the Reservoirs).