1. Geoffrey of Monmouth undertook to write a national history of Britain from its origin through the seventh century, some nineteen centuries of history by his reckoning. Arranged in twelve books, on the pattern of Vergil¡¯'s Aeneid (29-19 b.c.e.), Geoffrey¡¯s account traces the reigns of nearly a hundred British kings, beginning with the nation¡¯s mythical founder Brutus.
2. The original Trojans, Celts, and other tribes living in the land before the Roman conquest in the first century, as well as some Roman settlers, are all collectively labeled Britons. In Geoffrey¡¯'s account, they are arrayed against the Saxons, a collective name for the Germanic tribes that began invading the land in the fifth century.
3. Like many other medieval historians, he begins his narrative with the Trojan War, since he believed that the country was founded by a descendant of the Trojan princes who dispersed after the fall of Troy. Brutus, the mythic founder of Britain, is a great-grandson of the Trojan prince Aeneas, the legendary founder of Rome. Setting out from Rome in his odyssey, Brutus traveled to Greece, where he joined other Trojan exiles. In armed struggle against the Greeks, they conquered a third of the country, but, in the interests of avoiding further strife, they decided to embark for Britain after a prophecy of Diana directed them to do so. By sea, theymade their way to the island, defeated the giants who dominated the land, and founded a kingdom. They then proceeded to establish cities, including the capital Trinovant, later London.
4. Following the departure of the Romans, efforts to unite the kingdom proved unsuccessful. The story of Vortigern, Hengest, and Horsa, taken primarily from Bede, is narrated as a tale of violence and revenge that continues through generations of monarchs. Vortigern, an ambitious Briton, betrayed King Constantine and his son Constans. With the help of Saxon allies, whom he invited to England as allies against the Picts and other rebellious Britons, Vortigern seized the throne for himself. Constantine¡¯s two younger sons, Aurelius Ambrosius and Uther Pendragon, fled to Europe. An interest in prophecy led Vortigern to locate the youthful magician Merlin to seek his guidance.
5. By the beginning of book 7, halfway through the narrative, the groundwork is laid for the final portion. The last books introduce the reign of Arthur, portrayed as a Briton champion against the Saxons. Book 7 is entirely devoted to the ¡°Prophecy of Merlin,¡± a piece written by Geoffrey before he began the Historia regum Britanniae and incorporated into the narrative. The prophecy offers a mystical vision of the future that features symbolic dragons, animal imagery, and strange transformations. Taken as a whole, it is a troubling anticipation of chaos, without any clear resolution, though it is intended to foreshadow national history. Following the prophecy, the narrative resumes with an account of the two remaining sons of Constantine, who returned from exile, defeated Vortigern, and restored their line with Aurelius Ambrosius as king. Uther Pendragon led armies against enemies who were still in rebellion and became king after his brother was treacherously slain. Through the trickery of Merlin, Uther begat Arthur with Igerne, wife of Gorlois, duke of Cornwall, and, after Gorlois died in battle, married Igerne.
6. Books 9-11 are wholly concerned with the exploits of Arthur. A Briton leader against the Saxons, he became king while still a boy, united his nation, and gathered chiefs and kings from outlying and remote areas to his thriving court at Caerleon, later Camelot, on the Usk River. Having united his own nation, he ventured abroad to conquer Gaul and Norway, and, after refusing demanded tribute from Rome, led an English army to the continent in battle with the Romans. The Romans summoned monarchs from their eastern provinces to their aid, but to no avail. In a decisive battle, Lucius, the Roman emperor, was killed, though losses were heavy on both sides. Arthur lost two of his best knights, Kay and Bedivere. Later, he moved his army to the gates of Rome, before being called back to Britain by a treasonous rebellion fomented by his nephew Mordred.
7. Mordred raised an immense army of 800,000, but Arthur¡¯s war-hardened veterans prevailed against the huge force. A final great battle, alleged to have occurred in the year 542 by Geoffrey, led to the deaths of the mythic monarch and of Mordred. The queen entered a convent, and the Briton crown went to Constantine, son of the duke of Cornwall.
8. Following Arthur¡¯s death, other kings, notably Constantine, Cadwallo, and Cadwallader, continued the struggle against the Saxons, until a dire famine in the seventh century forced all but a few native Britons to abandon their native land. In 689, King Cadwallader, the last of the Briton line, died in exile in Rome. The Saxons gained dominance over the kingdom by returning and resettling before the native Britons. The narrative ends with prophecies that suggest the Britons will someday reclaim their land.