The author of Le Morte Darthur left remarkably few certain facts about himself. His own closing notes call him Thomas Malleorre or Maleore, describe him as a knight and a prisoner, and ask readers to pray for his release and later for his soul. The man who best fits those clues is Sir Thomas Malory of Newbold Revel in Warwickshire, born about 1416 into a landholding family with estates in Warwickshire and Northamptonshire. Other men named Thomas Malory lived in fifteenth-century England, so the identification is strong rather than absolute. The Newbold Revel knight, however, possessed the rank, education, imprisonment and chronology needed to match the author. He inherited family lands while still a young man and entered the violent political world of late medieval England at a time when military service, local power and noble patronage could shape a gentleman's entire future.

Malory's early career looked respectable. He served in Gascony, the English-held territory in south-western France, and was knighted around 1440 during military service. He became connected with Henry Beauchamp, Duke of Warwick, one of the leading nobles of the English Midlands, and in 1445 he was elected to represent Warwickshire in Parliament. That position placed him among the county's recognised political elite. Beauchamp died in 1446, however, removing an important patron just as Malory's life began to darken. England itself was moving towards the Wars of the Roses, the dynastic struggle between the houses of Lancaster and York, a conflict in which private quarrels, armed retainers and national politics repeatedly became entangled.

In January 1450 Malory was accused of laying an ambush for Humphrey Stafford, Duke of Buckingham, a powerful magnate whose lands and influence reached deeply into Warwickshire. More accusations followed. Records charged Malory with robbery, extortion, cattle theft, violent attacks and two rapes, as well as offences against Combe Abbey near his home. These are accusations preserved in legal records, not convictions reached after a modern-style trial, and the motives behind several cases remain difficult to recover. What is certain is that the charges destroyed the secure public life he had enjoyed in the 1440s. He spent much of the following decade moving between imprisonment, release, bail and renewed detention. For a knight of his social rank, such prolonged confinement was extraordinary.

The pattern did not end when Edward IV, the Yorkist king, took the throne in 1461. Malory obtained periods of freedom, but by the later 1460s he was again in custody. He was specifically excluded from Edward's general pardons in 1468 and 1470, yet the surviving evidence does not securely prove why. Earlier interpretations turned those exclusions into a simple story of Malory changing political sides and joining a Lancastrian conspiracy, but the documentary record does not justify that certainty. By the spring of 1469 he was confined in Newgate Prison in London. This final imprisonment gave the Arthurian author his clearest setting: a knight who had lived through armed politics, lawsuits, prison and civil disorder was now writing about a fellowship destroyed by divided loyalties and private vengeance.

Malory completed his great work during that imprisonment. His closing note dates the finished "hoole book" to the ninth year of Edward IV, between 4 March 1469 and 3 March 1470. He did not invent the Arthurian world from nothing. He worked with the Vulgate and Post-Vulgate Cycles, enormous French prose collections about Arthur, Lancelot and the Holy Grail; the Prose Tristan, a vast French romance centred on Tristan, Isolde and the Round Table; and English poems including the Alliterative Morte Arthure, which tells Arthur's continental war, and the Stanzaic Morte Arthur, which recounts the collapse of the fellowship. He selected, compressed and rewrote rather than merely translating line by line. Long French adventures could become short English episodes, while speeches, motives and moments of grief were sharpened into Malory's direct prose.

The result carries the reader across almost the whole Arthurian cycle. Uther Pendragon, Arthur's father, desires Igraine and fathers the future king through Merlin's disguise. Arthur proves his claim to the throne, builds the fellowship of the Round Table and fights wars at home and abroad. Lancelot rises as the greatest knight while his love for Queen Guinevere places personal loyalty against loyalty to Arthur. Tristan brings another destructive love story into the same court. Galahad, Perceval and Bors pursue the Holy Grail, the sacred vessel that tests the spiritual worth of Arthur's knights. The fellowship then breaks apart through accusation, revenge and civil war. Mordred seizes the kingdom, Arthur returns to fight him, Excalibur is cast back to the water, and the king disappears from the world he had built. Malory gives these inherited stories one recognisable English rhythm: ceremony followed by violence, loyalty strained by desire, and victories that carry the seed of later ruin.

The prisoner's own voice surfaces most clearly at the ends of sections. He asks his readers to pray that God send him "good delyveraunce" and describes himself as a knight prisoner. These pleas do not turn the book into autobiography, but they give its ideals of fellowship, mercy and imprisonment a particular force. Malory knew what a knight was supposed to be, and he also knew how far real political life could fall from that ideal. His Arthurian world is full of formal courtesies, sworn promises and ritual honour, yet it is equally full of ambushes, feuds, wrongful killings and men trapped by the consequences of earlier acts. The author never needs to explain the contrast. He lets the story show it.

Malory died on 14 March 1471, about a year after finishing the book. He was buried in the Franciscan church of Greyfriars near Newgate in London. His grave inscription remembered him as a valiant knight and linked him with Monks Kirby in Warwickshire, close to Newbold Revel. He therefore never saw his Arthurian work become a printed book. That happened in July 1485 when William Caxton, England's pioneering printer, produced Le Morte Darthur at Westminster. Caxton said that Malory had taken material from French books and reduced it into English. He also imposed the famous printed structure of twenty-one books and 507 chapters. The title by which the whole work became famous, Le Morte Darthur, was fixed by Caxton's edition even though Malory's own final wording refers more broadly to the whole book of King Arthur and his noble knights.

For nearly 450 years Caxton's printed text was effectively the Malory known to readers. Then in 1934 Walter Oakeshott, a librarian and teacher at Winchester College, found an unknown medieval manuscript while examining the college's books. The Winchester Manuscript had been copied by two professional scribes soon after Malory's death and preserved readings that differed substantially from Caxton's printing. Some passages were longer, some divisions were different, and Malory's own closing prayers appeared more clearly. The manuscript changed modern understanding of the work almost immediately. It also preserved a remarkable physical connection with early printing: reversed impressions of Caxton's type survive on several pages, showing that the manuscript had once been in or near his Westminster workshop before the 1485 edition appeared. The British Library purchased the manuscript from Winchester College in 1976, where it is now Additional MS 59678.

Malory's influence spread far beyond medieval England. Alfred, Lord Tennyson, the Victorian poet who wrote Idylls of the King, repeatedly returned to Malory when reshaping Arthur for the nineteenth century. T.H. White, the twentieth-century novelist who wrote The Once and Future King, built a modern Arthur from many of the same scenes and moral tensions. John Steinbeck, the American novelist, spent years adapting Malory in The Acts of King Arthur and His Noble Knights and modelled his presentation on the Winchester Manuscript. Films, novels, games and television have changed names, relationships and endings countless times, yet the familiar sequence of Arthur's rise, the Round Table, Lancelot and Guinevere, the Grail and the final betrayal still reaches modern audiences largely through the architecture Malory gave it. The knight-prisoner died before his book was printed, but the Camelot he assembled became one of the most durable imagined kingdoms in English literature.