The national flag of Wales is The Red Dragon (Welsh: Y Ddraig Goch). It consists of a red dragon, passant, on a green and white field. As with any heraldic charge, the exact representation of the dragon is not standardised and many different interpretations exist. The flag was granted official status in 1959, but the red dragon itself has been associated with Wales for centuries; indeed, the flag is sometimes claimed to be the oldest national flag still in use, though the origin of the adoption of the dragon symbol is now lost in history and myth. A plausible 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, but it could be even older. 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 recorded use of the dragon to symbolise Wales is from the Historia Brittonum, written around 830, but it is popularly supposed to have been the battle standard of Arthur and other ancient Celtic leaders. It is particularly associated in Welsh poetry with Cadwaladr king of Gwynedd from c.655 to 682.