The Lorteburn or Langbourne is a lost stream or river, which ran in the east of the City of London, arising near to Aldgate, flowing south near to the Tower of London, and discharging into the River Thames. The stream appears to have been covered over or dry by the early 14th century but its course has been discovered during archaeological digs in the area The stream gave its name to the Langbourn ward of the city. The river is seldom included on maps or lists of London's lost rivers, and its existence is denied by Nicholas Barton, in his 1962 book Lost Rivers of London, but in more recent work David Bentley argues for its existence.
Toponymy
The name Lorteburn is attested in a deed of 1288, when the stream was still extant. when it had been dry for nearly two centuries.
In English River Names, Eilert Ekwall identifies several instances of Lorteburn. He gives the derivation as from an Old English word meaning dirt or filth. Related to the Old Norse lortr ("excrement, faeces"), this implies a dirty or filthy stream, possibly one used for a sewer.
There is a second possibility given by Ekwall, a derivation from either the brook name Hlōra, or the mythical Norse female name Hlóra. The brook name derived from the Old English hlōwan meaning "The roaring one". This implies a swift stream with foaming water. This derivation may seem unlikely given the short length of the stream, but the watercourse was steep, and 'roaring' does correspond with Stow's description.
- 2-4 Jewry Street (Peter Rowsome 1980) a stream in a section cutting through the natural brickearth, on a north to south alignment.
- Rangoon Street (David Bowler 1982) two stream-beds were observed following differing courses.
Bentley interprets this evidence as <q>a stream called the Lorteburn recorded east of Seething Lane in the late 13th century.</q> giving the name as 'Langborne' and describing the route as running along Fenchurch Street, Lombard Street, and Sherbourn Lane. Stow states that the river gave its name to the Langbourn ward of the City of London. The stream was either covered over or dry by his time.
In 1770 John Noorthouck gives a similar description to Stow, with some additional details.
The church of St Katherine Coleman is indeed at the head of the course of the Lorteburn described by Bentley, but the rest of Stow and Noorthuck's descriptions are problematic given that they would require the water to flow uphill in the vicinity of Mincing Lane