Geoffrey of Monmouth


Geoffrey of Monmouth was born in the region of Monmouth in Wales. As such he is generally described as being a Welshman, but it has been suggested that one or more of his parents was from the region of Brittany in France.

From 1129-51 he was closely connected to events in Oxford where he was one of the secular Austin canons at the Collegiate Church of St. George. Twice he signed himself as a magister on charters, which implies he had some form of teaching role, but the University of Oxford did not yet exist.

In 1151 he was made the Bishop elect of Asaph, then a year later he was ordained as a priest at Westminster, and was consecrated a week later. In 1153 he was one of several bishops who witnessed the Treaty of Wallingford between King Stephen of England and Henry FitzEmpress, which helped end the Anarchy conflict.

He died in either 1155 or 1156, probably in London.

Education and Life Events

As with a large part of Geoffrey’s life, there are no sources that provide information about Geoffrey’s education.

Geoffrey’s relationships with high ranking clerical figures led him to write his works.

His knowledge of the Celtic language, due to his Welsh upbringing, contributed to his solicitation by Alexander of Salisbury, Bishop of Lincoln, Geoffrey’s local diocese, to translate a series of ancient Celtic prophecies into Latin. This he did, producing the Prophecies of Merlin. In the preface he praises Alexander, in the hope of gaining his approval and reward, but was disappointed. He also attempted to dedicate his magnum opus, The History of the Kings of Britain, to Alexander, but still received no reward. The reasons for these snubs are unknown.

Soon after Alexander’s death in 1148, Geoffrey wrote the Life of Merlin, and dedicated it to Alexander’s successor, Robert de Chesney, who had also been one of Geoffrey’s fellow canons at St. George.

Walter the Provost, Archdeacon of the city gave Geoffrey "a certain very ancient book written in the British language", and encouraged him to translate it into Latin. This translation would become the History of the Kings of Britain, which was completed in 1136. However, it should be noted that there is much debate about the existence of such a book, as no copy has been discovered. It has also been suggested that a large part of the content of the History of the Kings of Britain was embellished, or simply fabricated by Geoffrey.

Noted Works

  • The History of the Kings of Britain

Published: 1136

His most famous work, it was a history of Britain spanning 19 centuries. He focuses on three particular individuals:

  • The mythical Brutus, grandson of Aeneas, who, according to Geoffrey, discovered Britain
  • Belinus, who Geoffrey claims sacked Rome. However, historians agree that this did not occur.                                                                            Arthur, King of Britain, whom more than a fifth of the book is dedicated to. It should be noted that Geoffrey’s account of his life is closer to the stories of the Arthurian Legend, than the historical Arthur. More than a fifth of the book is dedicated to Arthur.

His works incorporated the histories of pagan peoples, such as the story of the siege of Troy, demonstrating how, well before the Renaissance and the ‘rediscovery’ of Ancient Greek and Roman civilizations and their scholars, writers on Antiquity remained greatly admired during the Medieval period. As such their work would have been seen as credible history by Medieval historians, including Geoffrey.

Some parts of the text are grounded in reality, some are more fantastical, particularly the chapters on King Arthur.

  • Prophecies of Merlin

Published: Sometime between 1129-1136

His first work, written for Bishop Alexander, was a translation of a collection of Ancient prophecies apparently made by Merlin.

  • Life of Merlin

Published: 1150/1

Further accounts of Merlin’s life, based on more source documents discovered or received by Geoffrey. This account did not corroborate what he’d written about Merlin in ‘The History of the Kings of Britain’, implying that what he’d written had been either invented or, he’d attached Merlin’s name to the actions of an unknown Royal Advisor. Also the events of ‘The Life of Merlin’ are set after Arthur’s reign, giving the title character an impossibly long lifespan.

Reputation and Impact

Though he wrote more than one book, the only one to have a significant influence was the Historia regum Britannie, The History of the Kings of Britain. A large part of this was due to his pro-British, and anti-Roman bias.

At the time, the work was taken at face value and accepted by most as a true history of the British people, particularly the Welsh, from around 1100 BC to around 689 AD. However, during the first half of the twelfth century his work was treated cautiously by other historians, who, for several reasons, were reluctant to incorporate Geoffrey’s work into their own surveys and the general overview of British history.

At the time, there was notoriously few original British sources from the pre-Norman conquest period. As such, Geoffrey’s claim to have access to a wealth of original information, which he incorporated into his work, caused a stir. His work was slowly accepted because it challenged previous conceptions about British history, often in controversial ways, such as his claim that the Britons conquered Rome three centuries before Julius Caesar’s arrival in Britain. Such claims, and his focus on other pseudo history topics, such as King Arthur and Merlin, led to great deal of criticism from orthodox 12th century historians. One in particular was William of Newburgh, who, writing in about 1190, said:

‘It is quite clear … that everything this man wrote about Arthur or his successors, or indeed his predecessors from Vortigern onwards, was made up, partly by himself and partly by others, either from an inordinate love of lying, or for the sake of pleasing the Britons.’

It should be noted that part of his historiography, though possibly written in aid of his pro-Briton stance, was progressive, and had a positive effect on the overview of British history. Before his works, the general consensus amongst historians had been that the Saxon rule of England began with the landing of the mercenary brothers, Hengist and Horsa, on British shores. However, Geoffrey interpreted it as a gradual migration of Saxon peoples over time to England that only saw them dominate the country after the 7th century. It caused historians to question the way they judged periodization, but like much of Geoffrey’s contribution, it wasn’t truly accepted until the second half of the 12th century.   

However, by undermining Hengist and Horsa’s contributions, he emphasized his pro-Briton stance. This was partly by stating that Arthur, whom he saw as Britain’s greatest ever king, died in 542AD, which was 93 years after the date normally assigned to their landing. As such he implied that their invasion failed to undermine the British domination of England. And it should be noted that this was partly affected by Geoffrey’s ideal of united British power under a united ruler. This meant that he somewhat glossed over the 8th and 9th centuries, a period that encompassed the fractured Saxon kingdoms and the Viking invasions. Incidents like this are one of several reasons why the validity of his account was debated, even after much of his work was widely accepted.

During the second half of the 12th century his works were more popularly received. This may be in part to an increased interest in ‘romantic’ history, a category in which the unorthodox Historia regum Britannie, with its focus on themes and near-mythical individuals, fitted into. However, it was during this time that the criticism from orthodox historians became more vocalized, particularly the aforementioned William of Newburgh. And such debate over the reliability of his work grew over the 14th, 15th and 16th centuries.

Geoffrey of Monmouth is recognized by modern historians more for his use of themes than his work’s historical inaccuracy. His work is recognized as a forerunner of Insular history, as he wrote his works on British history by just using British sources, deliberately ignoring the wealth of Roman sources that were available on the subject. As such he was able to create such a positive account of the Britons, which included fabricated British victories over the Romans, including the apparent sacking of Rome by Belinus.

Another theme was his belief that history had a cyclical nature. That humans with their free will could shape history, but history and Fortune also directed human action. This meant that in Geoffrey’s accounts, characters repeated mistakes others made before them. He often included basic situations e.g. feuds, British expeditions to Rome, illicit relationships, that have far reaching consequences. This also linked into his focus on how some leaders put their personal desires before the needs of the nation, and how only united, and led by a strong leader, was Britain powerful. And within that he also incorporated the theme of liberty, particularly in order to portray the Roman Empire in a negative light, and emphasize Britain’s right to be a free, powerful state.

Some historians believe that Geoffrey’s style of writing contrasted the typical Christian-moral history written by other historians. These writers usually portrayed God as a watchful presence, who allowed punishment and blessing to fall upon people according to their actions. However, some of Geoffrey’s content opposes that thesis, such as Vortigern, a wicked king who lusted after and married a Saxon pagan woman, and was later murdered at a peace parley with the Saxons. However, it should be noted that Vortigern was an enemy of Merlin, one of Geoffrey’s favorite protagonists. So his death may have been used by Geoffrey to demonstrate the retribution that falls upon those who opposed the heroes of his works, as well as demonstrate the consequences of bad kingship. 

Bibliography/Reading List

Geoffrey of Monmouth, ‘The History of the Kings of Britain’ (Penguin Books LTD, London, 1966)

Robert W. Hanning, ‘The Vision of History in Early Britain: From Gildas to Geoffrey of Monmouth’ (Columbia University Press, London, 1966)

R. William Leckie, ‘The Passage of Dominion: Geoffrey of Monmouth and the Periodization of Insular History in the Twelth Century’ (University of Toronto, London, 1981)

Oxford DNB article: Geoffrey of Monmouth:

Geoffrey of Monmouth:


Jordan Hixson