[HM Queen Catherine]

Originally Posted by Jo of Palatine

That was part of my idea: if it is politically opportunate, could the Welsh Assembly ask the new king to keep his title of Prince of Wales or could parliament in London declare that Charles still holds the title of Prince of Wales in addition to being king of the UK?

The title of Prince of Wales must be created for each male heir to the throne, because if the heir subsequently inherits and becomes Sovereign, the title then merges with the Crown. From that point forward, the title invested in the man who is now monarch ceases to exist. There is no further Prince of Wales until it is invested in the next male heir.

This title is in the gift of the Sovereign and may only be granted by the Sovereign. It is held separate from any inheritable titles of the heir, precisely because the title is destined to merge with the Crown, and the investiture reserves the special status of Wales within Great Britain. Even if a Prince of Wales dies without becoming King, the title goes back to the Crown, and may only be re-invested as the gift of the reigning Sovereign.

If, for instance, Prince Charles pre-deceases the Queen, then the title "Prince of Wales" would have to be re-created for Prince William, even though he is currently known as Prince William of Wales. There is a distinction between being a "prince of Wales" and "The Prince of Wales". Officially, Charles is HRH The Prince Charles, The Prince of Wales. If and when William is invested, he will be HRH The Prince William, The Prince of Wales.

It is also important to remember that females, even if they are the next in line to the throne, may not be invested in the Prince of Wales title.

Originally Posted by Jo of Palatine

It really is not important if there is a duke of "York" or "Edinburgh" or "Gloucester" as there is no duchy and never was historically.

That depends on your meaning that these titles were never duchies historically. A peerage was originally considered to be a landed title, from which the holder can derive or collect income, and has authority over the people living in his landed estates.

The Duchy of York was first created in 1385, and was a landed dukedom until it merged with the Crown in 1461, when the holder became Edward IV. There have also been several Earls of York in medieval times. Since 1461, it has traditionally been the title for the second son of the Sovereign.

The Duchy of Gloucester was also first created in 1385, and was a landed dukedom. The first three dukes all died without issue, and afterwards it was considered unlucky, and was not granted again for 150 years.

The Duchy of Edinburgh has existed since 1726, and to all intents and purposes, is not a dukedom in the sense of the two others, however, it was supposedly a source of income for the initial holders of the title.

Originally Posted by Jo of Palatine

But there was a principality of Wales like there was a kingdom of England and one of Scotland.

This is quite true, there was a Principality of Wales, but there were very few men that were actually "Prince of Wales" and recognized by the English Crown. The principality was divided into several separate kingdoms, and each had their own prince - the Prince of Gwynedd, for example.

Prior to the Norman Conquest, the most powerful Welsh ruler of any given time was known as "King of the Britons". In the 12th and 13th centuries, the title evolved to that of Prince of Wales.

The last native Prince of Wales was Owain Glydwr, who was proclaimed Prince in 1400. His short reign ended in 1409.

Originally Posted by Jo of Palatine

But what about Wales? At the moment Wales is treated as a conquered country who was included into England. While I don't believe that Wales and the UK will go their separate ways in the near future, it would be a nice gesture by Charles to declare himself the heir of the Welsh princes by keeping his title, and not behave as the heir of their conquerors.

Unfortunately, Wales is a conquered country, just like Ireland, and Ireland never even had a special designation. The Sovereign, of course was known as the Lord of Ireland until the time of Henry VIII. Prior to that, the country was under the guardianship of the Pope. When Henry broke away from the Catholic Church, he declared himself King of Ireland, as did subsequent monarchs. But for the Irish, there has never been a "Prince of Ireland" as there has been a Prince of Wales.

The United Kingdom of Great Britain consists of England, Scotland and Wales. Even if there were a Welsh Parliament, I doubt they would request that the Prince of Wales keep his title after becoming King. And I doubt the British Parliament would overturn centuries of tradition, even if such a request were made.

The special status of Wales is that they "hold the heir of the Crown", and they do so exclusively. The Prince of Wales is not the Crown Prince of Scotland, nor is does he hold a title in Northern Ireland. Hereditarily speaking, he doesn't hold an Irish title at all.

At least with Wales, they have their own Crown Jewels, which are separate from the Crown, and known as the Honours of the Principality of Wales. Wales has historically retained its special status within the kingdom of Great Britain, and likely will continue to do so.