The Fleet, also known as the Holbourne (hence Holborn) is one of several small tributaries of the Thames that used to
flow through London, and are now bricked over and buried underground. The Fleet is the longest: it begins in two springs on
Hampstead Heath, flows through a series of linked ponds and then disappears underground for the whole of the rest of its
five-mile course down through Kentish Town, Kings Cross, Clerkenwell and Holborn to the Thames at Blackfriars. Once
it was a navigable river at least as far as Kings Cross: an anchor dating from around 1400 was found at Battle Bridge, the old
name for the Kings Cross area, taken from the bridge over the Fleet where Boadicea was supposed to have been defeated
by the Romans. Where the Fleet met the Thames was once an estuary four hundred feet wide lined with busy wharves.
So what happened to it? As early as the thirteenth century inhabitants of London were complaining about the foulness of
the Fleet, which became more and more polluted as the city grew larger. Along the Fleet valley lay some of the worst slums
in London and most of the city's prisons: the Cold Bath Fields prison in Clerkenwell, Newgate, where public executions
were held; the Middlesex House of Correction; Fleet and Ludgate prisons; and Bridewell prison in Blackfriars. By the beginning of the eighteenth century the
Fleet was being blamed for outbreaks of disease: its lower reach, contaminated by tanners and sugar-bakers and rotting offal
from the carcasses of Smithfield market, was virtually an open sewer running through some of the worst slums in London, and
its stench was notorious. Jonathan Swift wrote about what happened when the Fleet rose after a storm:
"Sweepings from Butchers Stalls, Dung, Guts and Blood,
Drown'd Puppies, stinking Sprats, all drench'd in Mud,
Dead Cats and Turnip-Tops come tumbling down the Flood".
Much of London was still in a state of disrepair from the
Great Fire of 1666. As part of his rebuilding plan the city's architect, Sir Christopher Wren, came up with a plan to improve
the Fleet, and convert its lower reach into a classical waterway along the lines of Venice, which would be called the New
Canal. It was a grand plan which included steeper, stone-cut embankments and four elegant new bridges at Bridewell, Fleet
Street, Fleet Lane, and Holborn. It was completed in 1780 at a cost of £74,000.
Unfortunately Wren failed to address the problem of pollution, and although the river looked a lot better, it still stank. The
New Canal lasted for around fifty years and was then ordered by Parliament to be paved over in 1732. When the Regents
Canal and Camden Town were developed in around 1812, that section of the Fleet was buried too, and later the railways came
and buried the Farringdon valley under Farringdon Road. The last above-ground part of the Fleet - from the source down
through Hampstead - was finally covered over in the 1870s when Hampstead was developed as a suburb. Now the river survives only in a few streetnames, like Fleet Street, and tales of floods in the basements of old buildings.