Notes

The flag was granted official status in 1959, but the red dragon itself has been associated with Wales for centuries, though the origin of the adoption of the dragon symbol is now lost in history and myth. A possible theory is that the Romans brought the emblem to what is now Wales during their occupation of Britain in the form of the Draco standards borne by the Roman cavalry, itself inspired by the symbols of the Dacians or Parthians. The green and white stripes of the flag were additions by the House of Tudor, the Welsh dynasty that held the English throne from 1485 to 1603. Green and white are also the colours of the leek, another national emblem of Wales.
The oldest known use of the dragon to represent Wales is from the Historia Brittonum, written around 830; the text describes a struggle between two serpents deep underground, which prevents King Vortigern from building a stronghold. This story was later adapted into a prophecy made by the wizard Myrddin (or Merlin) of a long fight between a red dragon and a white dragon. According to the prophecy, the white dragon, representing the Saxons, would at first dominate but eventually the red dragon, symbolising the Britons, would be victorious and recapture Lloegr. According to the legend, this victory would be brought about by Y Mab Darogan. This is believed to represent the conflict in the 5th and 6th centuries between the Britons and the invading Saxons. A version of the tale also appears as part of the poem 'Cyfranc Lludd a Llefelys' in the Mabinogion. One twelfth-century account of this is Geoffrey of Monmouth's Historia Regum Britanniae, where he states Merlin's prophecies.The red dragon is popularly believed to have been the battle standard of Arthur and other ancient Celtic/Romano-British leaders. There is considerable evidence to suggest that during this period the dragon was a symbol of the Romano-British monarchy and possibly Romano-British society more broadly, including some from Anglo-Saxon poetry. The dragon is particularly associated in Welsh poetry with Cadwaladr king of Gwynedd from c.655 to 682. The Dragons of Arthur and Cadwaladr were possibly based on the draco standards carried by Roman cavalry units stationed in Britain. The Draco originated with the Sarmatians, a unit of whom were stationed in Ribchester from the 2nd to 4th centuries.

Despite the close link throughout early Welsh history, the dragon was not used exclusively as a symbol for Wales during this period, and it was used throughout Britain as a symbol of authority. In 1138, it was adopted by the Scottish as a royal standard, and Richard I took a dragon standard to the Third Crusade in 1191. Henry III fought under the dragon at the Battle of Lewes and it was used later by Edward III at the Battle of Crécy.n 1400, Owain Glyndŵr raised the dragon standard during his revolts against the occupation of Wales by the English crown. Owain's banner known as Y Ddraig Aur or "The Golden Dragon" was raised over Caernarfon during the Battle of Tuthill in 1401 against the English. The flag has ancient origins, Glyndŵr chose to fly the standard of a Golden dragon on a white background, the traditional standard. Fifteen years later the English crown, under the rule of Henry V, used the red dragon standard itself during the Battle of Agincourt. The English forces during the battle utilised Welsh longbowmen, along with their own archers. In 1485, the most significant link between the symbol of the red dragon and Wales occurred when Henry Tudor flew the red dragon of Cadwaladr during his invasion of England. Henry was of Welsh descent and after leaving France with an army of 2000, landed at Milford Haven on 7 August. He made capital of his Welsh ancestry in gathering support and gaining safe passage through Wales. Henry met and fought Richard III at the Battle of Bosworth, and in victory took the English throne. After the battle, Henry carried the red dragon standard in state to St Paul's Cathedral, and later the Tudor livery of green and white was added to the flag.
Modern use
In 1807, the red dragon on a green mount was adopted as the Royal Badge of Wales, and on 11 March 1953 the motto Y Ddraig goch ddyry cychwyn ('The red dragon gives impetus' or 'The red dragon leads the way') was added, a line from the poem by Deio ab Ieuan Du. The badge was the basis of a flag of Wales in which it was placed on a horizontal white and green bicolour. In 1959, government use of this flag was dropped in favour of the current flag at the urging of the Gorsedd of Bards. Today the flag can be seen flying from the Senedd in Cardiff, and from the Wales Office in Whitehall, London each day.