460 CE - 560 CE: Probable dates for historical Arthur, King of the Britons.

830 CE: Welsh Historian Nennius first mentions Arthur as king and hero of Battle of Badon Hill.

1095 CE - 1143 CE: Life of historian William of Malmesbury who mentions Arthur as war-chief of Britons, not king.

1130 CE - 1190 CE: Life of French Poet Chretien de Troyes who introduces Grail Quest, Lancelot, and other elements to Arthurian Legend; calls sword Escalibur.

1136 CE: Geoffrey of Monmouth's History of the Kings of Britain introduces Arthurian Legend and Arthur's sword as Caliburn.

1160 CE: French Poet Wace develops Arthurian Legend further, adds Round Table, calls sword Chaliburn.

1170 CE - 1220 CE: Life of German Poet Wolfram von Eschenbach who develops Arthurian Legend in his poem Parzival.

1190 CE: French Poet Robert de Boron develops Arthurian Legend further including Grail Quest, Merlin, Sword in the Stone.

1190 CE - 1220 CE: Layamon translates Arthurian Legends into English.

1200 CE: The Welsh Mabinogion influences development of Arthurian Legend.

1210 CE: Gottfried von Strassburg writes Tristan, contributes to Arthurian Legend.

1215 CE - 1235 CE: The Vulgate Cycle of the Arthurian Legend composed in English Prose; Arthur's sword is Excalibur.

1469 CE: Sir Thomas Malory composes Le Morte D'Arthur, definitive version of Arthurian Legend including Excalibur as the king's sword.

1485 CE: Le Morte D'Arthur published by William Caxton, becomes instant best-seller popularizing Arthurian Legend.