Banner of Owain Glyndwr

The lion on red and gold was carried into battle during Owain Glyndwr's rebellion against the English.

Although the design has since become synonymous with the legendary Welsh warrior, its origins are unclear.

It has also been claimed that Glyndwr hoped to demonstrate his lineage from the princes of Gwynedd, whose flag in the 13th century had been four passive lions. By making the lions rampant, Glyndwr was giving out a clear signal.

The standard bears a marked similarity to the arms of Llewelyn ap Gruffydd, the flag of the royal house of Gwynedd. Llewelyn was the last prince of Wales prior to its conquest by Edward I.

It has also been claimed that the design was developed from the arms of Powys Fadog, where his father was a hereditary prince, and the coat of Dehuebarth, from which his noblewoman mother came. The Powys Fadog arms were a red lion on a gold background; those of Deheubarth were a gold lion on a red background.

The banner of has enjoyed a resurgence in popularity in recent years. It is often seen at major sporting events, and has become a potent symbol of protest.

A variant of the design is still used as the Prince of Wales' standard for Wales.