The Welsh Kingdom has various flags, banners and badges representing different eras, organisations and bodies.
The National Flags
The national Flag of Wales used by the Kingdom of Wales since 1400 is the Golden Dragon Rampant flag. Originally flown as the War Banner of Owain Glyndwr during the War of Welsh Independence it became the banner used by Owain during his time as Prince and later by his son, Maredudd, first king of Wales to indicate the Kings presence. In the first raft of laws passed following the 1796 restoration of Welsh independence the flag was recognized as Wales' national flag.
The Cross of St David has also been used as alternative Welsh flag by the Welsh state since independence in 1409. Used initially by the Senedd its use spread to the Welsh Navy when it was adopted as the Naval Jack. It was then used by the English as their "Welsh Flag" following the Treaty of Manchester and the union of the English & Welsh kingdoms. Used for the period of the English occupation (1718-96) the flag featured both on its own and as part of a British Union Flag. Following the Welsh Restoration, the flag fell from popular usage, but with the African adventure and the taking of Portuguese Guinea for Wales, the colonists needed a flag. The only one available were the ships naval jacks. Defacing one of them with the Portuguese arms for Guinea, the first Welsh colonial ensign was born. Its usage then spread across the Atlantic to Y Wladfa and it was then recognised as the Colonial Ensign for the Welsh Empire. The tricolour flag as based on the flag used by Prince Rhys during the Welsh Civil War (which had a black star rather than a gold one. The communist party added the cog with hammer and sickle and this flag briefly became the Welsh flag in 1950.
The Royal & National Coat of Arms of Wales
Derived from the 1st War of Welsh Independence, when Owain Glyndwr first raised his banners in defiance of the English Crown he did so under the combined Lions of the Houses he was heir to. As scion of the House of Mathrafal and a descendant of the House of Dinefwr he combined the lions onto a counter-charged Red and Gold field. The House of Glyndwr (a cadet branch of Mathrafal) would go on to rule Wales from 1400 to 1599, firstly as the House of Mathrafal (Owain IV), then as the House of Glyndwr (1419-1555) and finally as the House of MacGregor-Glyndwr (1555-99).
At the end of the 1st War, as part of the Treaty of London, Owain IV chose to use the countercharged arms as his Princely arms. Maredudd readopted these arms following his coronation as king of the Welsh in 1428. These arms (the simple four lions rampant or the Arms of Glyndwr) are still the arms of the modern nation-state of Wales.
The House of Deheubarth (a cadet branch of the House of Glyndwr and therefore Mathrafal) took power in 1600 and lasted until 1755 (1718 de facto). The new monarch, although a grandson of Queen Elen, chose to represent his new dynasty using the revived arms of his father, who had been created Duke of Deheubarth by his mother. As such Dafydd IV changed both the Royal and the National arms used within Wales. The Royal Arms were altered to the single Gold Lion Rampant of Deheubarth, whilst the National Arms were the Arms of Glyndwr defaced by a crowned royal shield containing the Arms of Deheubarth.
During the Regency period (1750-55) following the death of the last Deheubarth king (Rhys) the national arms were again changed. The arms reverted to the Arms of Glyndwr with a single diagonal white stripe.
Following the election of Rhisiart of Morgannwg to the kingship, the arms were again changed. To reflect both his uncrowned state and that Wales was still under the rule of the British, Rhisiart continued to use just the Arms of Morgannwg to represent his crown. This continued throughout the period of the 2nd War of Independence (1759-96).
With the Treaty of Shrewsbury (1796) and the full restoration of the Welsh State, Arthur had also restored the ancient arms of Wales. Following the precedent set by Dafydd, Arthur retained the use of the uncrowned Arms of Morgannwg as the arms of the Principality of Morgannwg and the position of Prince, whilst using a Crowned Royal Shield defacing the Arms of Glyndwr as the Royal Standard of Wales.
This was ratified at the same time as the National Flag and has remained so since then. The Communist Government in the 1950's attempted to change the official Coat of Arms with the White Eagle emblem, but were removed from power by royalist pro-American forces before being able to implement these changes.
As such Wales, in line with many other European monarchies has a National Arms and a separate Royal Arms. The National Arms consists of the arms of the House of Glyndwr unaltered. The Royal Arms of Wales consist of the Arms of Glyndwr defaced by the Arms of Morgannwg.
Other Arms of Wales
During the reign of Dafydd V, the Royal Arms were altered by Dafydd to fit his claim to the British throne. For this he removed the crowned crest and added the British arms to the 4th quarter of the arms.
The other arms are the "Union" arms of 1720-1796 whereby Wales was represented in the British Royal Arms.
The State Flags of the Welsh Regions
Following the 1850 reorganisation of the Welsh regions the Senedd commissioned flags to represent each of the regions of Wales. These flags were based on the German/Austrian state flags and consist of a green and white background. There are three variants of the background. One is "white & green horizontal", the other "green and white horizontal" and the final one is "green & white vertical". There are four flags which do not follow this colour pattern (Penfro, Gwlad y Haf, Ddena & Y Mers) whilst the flag for Dyfnaint Glan Hafren is a point of contention between Britain and Wales as it proclaims the Welsh territorial ambitions on Cornwall.
Other Flags of Wales
During the Imperial Era, Wales also used several flags to represent the various colonies.
The page for these flags is here Welsh Empire Colonial Flags
There is also a page for the military flags and banner of Wales