The Isis

"The Isis" is an alternative name for the River Thames, used from its source in the Cotswolds until it is joined by the Thame at Dorchester in Oxfordshire. The modern form of the name, first recorded c.1540, relates to the Egyptian goddess Isis. The deity was venerated throughout the Roman Empire, and was worshipped at the Temple of Isis – near the Thames in Londinium – during the Roman occupation. Notably, the Isis flows through the city of Oxford.

Egyptian goddess
The association between Oxford – rowing, angling – and the Egyptian goddess Isis – might be explained by her role as Stella Maris – "Star of the Sea" ..."the divine protector of sailors and fishermen". The Latin Stella Maris – "Star of the Sea" – relates to Mary, mother of Jesus and Christianity. The worship of Isis (as Stella Maris) was associated with the transformation of Roman society – away from paganism – towards the shining light of Christianity.

Oxford is famously known as the city of "dreaming spires" for the stunning architecture of its many churches. The University of Oxford has always been an important centre for the study of religion.

Rowing
The name "Isis" is especially used in the context of rowing at the University of Oxford. A number of rowing regattas are held on the Isis, including Eights Week, the most important Oxford University regatta, in the Trinity term (summer), Torpids in the Hilary term (early spring) and Christ Church Regatta for novices in the Michaelmas term (autumn). Because the width of the river is restricted at Oxford, rowing eights normally have a staggered start near Donnington Bridge and must then aim to "bump" the eight in front (i.e. catch up and touch or overlap with it sufficiently). The leading eight aims to "row over" (i.e. finish the race without being bumped). There used to be ornate wooden barges on the river bank at the southern end of Christ Church Meadow to house rowing facilities and for viewing races. Now the barges are gone and there are boathouses instead a little further down the river near the confluence with the River Cherwell. Poplar Walk in Christ Church Meadow is used as a route to and from the boathouses.

The name "Isis" is also used for the men's second rowing eight of Oxford University Boat Club, who race against Goldie, the men's second crew of the Cambridge University Boat Club, before the annual Oxford vs. Cambridge Boat Race on the Thames in London.

Angling
The Isis, like much of the Thames, has long been popular among anglers for its freshwater fish, including trout and crayfish. The Oxford region is home to several angling clubs. W. F. Wallett, a popular Victorian clown, shares in his memoirs his own anecdote about fishing in the Isis with the celebrated circus proprietor Pablo Fanque: "For a few days I amused myself with Pablo Fanque fishing in the Isis. Pablo was a very expert angler, and would usually catch as many fish as five or six of us within sight of him put together. This suggested a curious device. You must know that Pablo is a coloured man. One of the Oxonians, with more love for angling than skill, thought there must be something captivating in the complexion of Pablo. He resolved to try. One morning, going down to the river an hour or two earlier than usual, we were astonished to find the experimental philosophic angler with his face blacked after the most approved style of the Christy's Minstrels."

Natural England maps
The name Isis is normally associated with the stretch of the Thames between North Oxford and its confluence with the River Thame at Dorchester on Thames:

Thame and Isis


The keystones of Henley Bridge depict carved faces intended to represent the Isis and the Thame. Thame is a bearded man, while Isis is female.

Dorchester
The Isis is an alternative name for the stretch of the Thames from its source in the Cotswolds – near Thames Head – to its confluence with the River Thame at Dorchester on Thames.

It has in the past been conjectured that the Romano-British name for the Thames ("Tamesis") is a conflation (joining together) of its two main tributary names:
 * 1) Tam – River Thame (Tame 956).
 * 2) esis – The Isis.

The conflation theory might explain the reason why the Thames has retained a trailing 's' – but the River Thame has not.

Scholars
The conflation theory (Tam + Isis) was proposed and endorsed by antiquarians and scholars during the middle ages:


 * 1) Ranulf Higden (c.1280–1364).
 * 2) John Leland (c.1503–1552).
 * 3) William Camden (1551–1623).

In the late seventeenth century, the Welsh scholar Edward Lhuyd – second Keeper of the Ashmolean Museum in Oxford – endorsed the conflation theory in Parochailia (1695).

Iron age
During the Iron age, a major river system might have passed through the territory of more than one tribe, each tribe having its own name for their stretch of river. River names are often ancient, dating back to the Celtic Britons before the arrival of the Anglo-Saxons.

The tribal territories for the Thames valley:
 * 1) Dobunni – Upper Thames.
 * 2) Corinium Dobunnorum (Cirencester).
 * 3) Source of the Isa.
 * 4) Glevum (Gloucester).
 * 5) Aquae Sulis (Bath).
 * 6) Catuvellauni – Lower Thames.
 * 7) Thame (Tame 971).
 * 8) Dorchester on Thames.
 * 9) Londinium.

The name used by the Dobunni for their stretch of the Thames is not known. However the etymology for names recorded during the medieval period indicate a Brittonic (P-Celtic) origin. The native language of the Dobunni ("the Britons") was Brittonic.

Roman Britain
The Thames rises from its source near Cirencester and begins its journey through the Cotswolds towards the Thames Estuary. During the Roman occupation, Corinium Dobunnorum (Cirencester) was the second largest Roman town in Britain, and Londinium the largest. The valley of the upper Thames was the most prosperous part of Roman Britain, it contained the highest concentration of Roman villas, and the most luxurious, for example Chedworth Roman Villa.

Temple of Isis
It is known that people in Londinium worshipped the Egyptian goddess Isis at the Temple of Isis, during the Roman occupation.

The graffito on a first-century flagon, found near the River Thames in Londinium, reads: ""LONDINI AD FANVM ISIDIS" ..."To London at the temple of Isis"."

North Britain
The name Isis is also found in North Britain:


 * 1) The Romano-British name for the River Tees – Teisis (or Teesa).
 * 2) The Isis Parlis caves beside the River Eamont, near the Roman fort Brocavum.

It is possible that the Romano-British name Teisis (or Teesa) may share a common etymology with Ptolemy's Tuesis in Caledonia. If so then the name derives from the Gaulish deity Esus ("God of the river") – not the Egyptian goddess Isis.

Post Roman
Following the end of Roman rule in Britain, towards the end of the fourth century, the Dobunni regained control of their traditional tribal territory, which happened to include some of the most prosperous parts of Roman Britain:


 * 1) Corinium Dobunnorum (Cirencester).
 * 2) Glevum (Gloucester).
 * 3) Aquae Sulis (Bath).

It would be expected that during the late sixth century the Saxon invaders would try to occupy and control the most important parts of the Roman infrastructure. There were battles between the Dobunni ("the Britons") and the Saxons, most notably the Battle of Deorham in 577. It is possible that there was some integration between the Romanised Dobunni and the Saxon Hwicce, while others abandoned the Dobunnic capital (Corinium Dobunnorum) and reestablished themselves in the available hill forts in the surrounding area. Archaeological evidence suggests that Crickley Hill, on the Cotswold scarp near Cheltenham, was re-occupied during the post-Roman period.

The Saxon Hwicce then occupied and controlled the upper Thames area:
 * 1) East of Thames Head (near Corinium) as far as Wychwood (near Woodstock and Oxford).
 * 2) West of Thames Head as far as the Forest of Dean.

Middle ages
Known name variants for the upper Thames, recorded during the medieval period, include:
 * 1) Ysa or Usa (14th century).
 * 2) Isa, Ise (14th century).
 * 3) Isis or Ouse (16th century).

The name variants Isa, Ise, suggest a P-Celtic origin and may derive from Brittonic  'is'  or  'isca' , from whence many common river names derive. The European Danube river was known by its Celtic name Istros. A more local example is the River Isbourne, which is a hybrid of Brittonic  'is'  and English bourne.

See also wiktionary – for Q-Celtic Usa, Ouse:
 * 1) Old Irish  ..."water".
 * 2) Scottish Gaelic  ..."river, stream".

Modern name
The modern form of the name, first recorded c.1540, is a reference to the Egyptian goddess Isis, possibly the result of a revival of interest in classical Roman antiquities during the sixteenth century, and influenced by the ideas of the antiquarian John Leland (c.1503–1552), who endorsed the conflation theory (Tam + Isis). It is unlikely that the earlier names were related to the Egyptian goddess.

The origin of the modern form was possibly influenced by:
 * 1) The study of religion at the University of Oxford.
 * 2) The association of the Egyptian goddess with Christianity.
 * 3) The association of the Thames with the Egyptian goddess.
 * 4) Events in the sixteenth century.
 * 5) The revival of interest in classical Roman antiquities.
 * 6) The conflation theory (Roman Tamesis = Tam + Isis) endorsed by the antiquarian John Leland.

It is possible that the earlier name Isa had a different meaning that was lost when replaced by a similar sounding name.

Example (River Severn)
The River Severn is a famous example of how the original meaning of a name is lost when it is replaced by a similar sounding name that has a different meaning.

Name legacy
The Morris Isis name was first used by Morris Motors Limited of Oxford on a six-cylinder car made from 1929 to 1931. It was resurrected on a six-cylinder car from the British Motor Corporation in the 1950s. The name died out in 1958.

HMP Isis is a Category C Young Offenders Institution in England operated by His Majesty's Prisons adjacent to HMP Belmarsh and HMP Thameside near the River Thames in the Woolwich area of South East London.

Each of the Formula Student cars manufactured by the Oxford Brookes racing team used the name ISIS in the beginning of its chassis number. ISIS is then succeeded by the year number; for example, ISIS XII was the 2012 chassis, nicknamed "Miss Piggy". This continued until the 2016 season, when the naming convention changed to use an OBR prefix.

The ISIS neutron source is named after the river Isis.