Timeline

This timeline spans events from Roman Britain to the present time; thus, all events are A.D. Some dates are for non–historic events (i.e., mythical).

Year	Event
360	Picts and Scots cross Hadrian's Wall and attack Roman Britain; brief British pagan revival in countryside as reaction to Emperor Julian's rejection of Christianity.
363	End of Julian's reign.
364	Roman Empire divides into East (based at Constantinople) and West (still centered on Rome); Valentinian I emperor in West.
367	Northern Confederation launches series of attacks on lines of Roman fortifications until 383— Hadrian's Wall overrun, Count of Saxon Shore and Duke of Britain crushed.
369	Valentinian sends Theodosius to restore order in Britain.
370	Theodosius drives Picts and Scots out of Britain, restores walls and forts, establishes signal stations along the Yorkshire coast, giving peace to towns and villas for at least a quarter of a century.
375	End of the reign of Valentinian I.
378	Adrianople falls to the Visigoths; beginning of the reign of Theodosius I.
382	Magnus Maximus repels the Caledonians at Hadrian's Wall.
383	Magnus crosses the channel to assert his claim on the purple, taking many of the British troops; consequentially northern Britain is threatened by Picts and Scots although Hadrian's Wall holds; Conan is king in Brittany.
388	Magnus is executed, along with son Victor.
c. 390	Saint Patrick is born on west coast of Britain.
392	Theodosius reunites the Empire.
395	Empire redivides; Theodosius dies and 10–year–old Honorius made emperor.
396	Northern Confederation launches offenses across the firths; General Stilicho sent to campaign against the Caledonians.
c. 397	Founding of Western monasticism; St. Ninian builds Candida Casa. Rome completes withdrawal from Hadrian's Wall.
401	Troops withdrawn from reaches of the Empire to defend Italy against Visigoth Alaric.
405	Niall of the Nine Hostages dies.
406	Britons elect Marcus and then Gratian to the purple, who are both quickly executed.
407	Constantine III crosses to the continent with all the troops he can muster; Burgundians penetrate far into Gaul and Spain, cutting off communication between Britain and Rome; Saint Patrick escapes slavery in Ireland.
410	Alaric invades and sacks Rome; beginnings of alchemy with the search for the Philosopher's Stone and the Elixir of Life; Honorius sends message to Britain that it is on its own.
411	Constantine III is slain.
417	Temporary Roman reoccupation (theory— improbable)
418	Pelagianism is ruled heresy by the church
423	End of the emperor Honorius' reign.
425	Beginning of Saint Patrick's ministry in Ireland and Saint Illtud's ministry in Wales.
426	Emergence of local leaders in Britain, such as Vortigern.
428	Saxon warships off east coast of Britain
429	Picts and Scots expelled from Southern England by Saxon mercenaries; Saints Germanus and Lupus are sent to Britain to conquer Pelagianism.
432	Roman currency no longer in circulation; Saint Niniane dies.
440	Town of Ys in Brittany submerges.
441	Beginning of Saxon incursion.
442	Hengist's massacre.
446	Last British request for military aid, sent to Aetius.
449	Germanus and Lupus sent again to conquer Pelagianism.
450	Anglo–Saxon warships attack Britain's east coast.
451	Attilla and the Huns invade Western Europe; St. Genevieve saves Paris.
456	Britons suffer a defeat by the Saxons at Crayford, Kent, and flee to London.
460	Presumed start of Aurelius Ambrosius' reign.
461	Saint Patrick dies.
462	Saint David, patron saint of Wales (462–547)
480	Reign of King Cerdic of "Wessex" (fl. 480–495)
482	Battle of Ocha in Ireland.
491	Saxons capture Pevensey, Sussex.
495	Kingdom of Wessex founded; King Cerdic dies; reign of Illan, Irish king who conducted raids on Britain (fl. 495–511)
500	Gildas born at Dumbarton.
504	Elevation and ordination of St. Dubricius.
510	death of Domingart, first Irish king of Dalriada.
515	Lull in the account of the Saxon conquest.
518	Account in the Annales Cambriae states "the Battle of Badon, in which Arthur and the Britons were the victors"
520	Reign of Gwynedd's Maelgwyn (fl. 520–551)
c. 525	Beowulf's victory over the dragon.
527	Justinian is emperor until 565
531	Comet reported.
539	The Annales Cambriae states "the strife of Camlann in which Arthur and Mordred perished"
540	Gildas writes his book recounting the twelve great battles later attributed to Arthur; Ida is king of Bernicia.
545	End of the reign of King Hoel of Armorica.
547	Saint David dies.
550	Anglo–Saxons push to settle east of Southhampton–Edinburgh line.
551	Maelgwyn of Gwynedd dies.
552	Cynric takes Salisbury and establishes Wessex.
559	King Owain kills Ida of Bernicia.
565	Ministry of Saint Columba on Iona.
c. 572	Gildas dies.
573	King Rydderch's ascension; ministry of Saint Kentigern.
574	Battle of Arthuret (Arthurydd, "Arthur's Head"); inauguration of King Aidan of Dalriada by Saint Columba.
584	Meeting of Saints Columba and Kentigern.
600	First reference to Arthur by name in the "Goddodin" (poem)
673	Bede's Ecclesiastical History of the British People is written. Like Gildas' works, it does not mention Arthur.
c. 828	The Historia Brittonum names Arthur and gives a listing of twelve battles he is said to have fought.
c. 1000	Culhwch and Olwen, widely considered to be the first Arthurian romance, is written.
1050–1071	Hordes of Seljuk Turks sweep over the Byzantine Empire and capture Jerusalem.
1095–1099	The First Crusade retakes Jerusalem.
c. 1100	The Life of St. Padarn refers to Arthur as a "tyrant."
1113	French monks travel to Bodmin, and a fight breaks out when a crippled man seeking healing insists that King Arthur is still alive.
1125	William of Malmesbury records that Arthur's grave is a mystery, and "ancient songs fable that he is still to come."
c. 1129–1151	Geoffrey of Monmouth's name appears on six different British charters.
c. 1130–1150	The Life of St. Gildas by Caradoc of Llangarfan records a dispute between Arthur and Gildas.
c. 1136	The History of the Kings of Britain is completed, causing Arthur's legend to spread all over the Continent.
1144	Edessa, first of the crusader–states is lost. Eleanor of Acquitaine pledges thousands of her vassals to the Second Crusade, and shocks medieval society by joining it dressed in full battle armor.
1149	The Second Crusade is unsuccessful. Returning crusaders may bring back traditions of courtly love from the Arab world.
c. 1150	Geoffrey of Monmouth's second work, the Vita Merlini is completed.
c. 1150–1155	The Roman de Brut is written, adding the Round Table to the legend.
1160	Eleanor of Acquitaine's eldest daughter, Marie, is sent to the Avenay of Champagne to be educated. She later marries Henry, Count of Champagne, and becomes patroness to Chrétien de Troyes.
1170–1190	Chrétien makes his five contributions to the Arthurian Legend, recording the character of Lancelot for the first time.
1191	Monks from Glastonbury announce the discovery of King Arthur's tomb.
c. 1200	Robert de Boron writes his Joseph d'Arimathe and Prose Merlin, adding various details to the Grail legend, and various dimensions to Merlin's character.
c. 1215–1230	The Vulgate Cycle is written, containing elements of the loss of a sacred, religious symbol.
1278	The bones discovered at Glastonbury are transferred to separate caskets and moved to the great church at Glastonbury, by order of Edward I. Edward and his consort, Eleanor, visit the bones and put them on display before the high altar for all to see.
1485	William Caxton publishes Thomas Malory's Le Morte d'Arthur. Henry Tudor defeats Richard III in battle. People all over Britain interpret this as a sign that Merlin's prophecy of the Welsh regaining control of the Island is coming true.
1539	Henry VIII seizes control of Glastunbury Abbey, destroying the tomb and bones discovered there centuries before.
1542	John Leland visits Somerset and learns the tale that Cadbury Hill was once King Arthur's "Camallatte."
1607	William Camden engraves the cross found in the tomb at Glastonbury.
c. 1800	Revival of interest in the Medieval Ages.
1819–1925	W. Gunn, J. A. Giles, W. W. Comfort, and others translate several Arthurian texts and romances into English, making them available to the general public.
1842	Alfred, Lord Tennyson publishes his first Arthurian poem, also titled Morte d'Arthur. Parallels are evident between Arthur and Prince Albert.
1850	Tennyson is named Poet Laureate.
1861	Prince Albert dies, prompting Tennyson to continue his work. Princess Alice expresses her wish that Tennyson idealize her father in verse.
1862	Tennyson meets Queen Victoria, and the two strike a lifelong friendship.
1868	William Forbes Skene produces the first modern translation of many of the poems of the Four Ancient Books of Wales.
1885	Tennyson completes the final poem which will comprise his Idylls of the King.
1888–1911	J. Gwenogvryn Evans transcribes several ancient Welsh manuscripts, including the Four Ancient Books of Wales into fascimile editions, making their original, Middle Welsh text widely–available to scholars.
1935	Excavations by Ralegh Radford uncover evidence of an ancient Celtic center of worship at Tintagel.
1938	T. H. White publishes The Sword in the Stone.
1939	Britain enters World War II. The devastation shapes the future books which will eventually become White's The Once and Future King.
1957–1984	Geoffrey Ashe, Leslie Alcock, and others publish a series of works which renew interest in the history of the Arthurian Legend.
1963	Walt Disney Pictures adapts White's The Sword in the Stone into the animated film. Ralegh Radford finds evidence that monks did, indeed, discover a tomb at Glastonbury.
1965	The Camelot Research Committee is formed.
1966–1970	Excavations of Cadbury Hill promote interest in the Arthurian Legend.
1970–1983	Mary Stewart publishes her Merlin series. In 1983, fires at Tintagel uncover evidence of a royal citadel and center of trade there.
1975	Monty Python and the Holy Grail is released to positive reviews.
1995	The film First Knight is released.
1998	Hallmark, in conjunction with NBC Studios, produces the Merlin miniseries starring Sam Neil and Isabella Rossellini.
2004	The film King Arthur is released, loosely based on the historical figure Lucius Artorius Castus.
2008–2012	The BBC series Merlin receives positive reviews.