What royal title did the Prince of Wales later hold?

The title that the Prince of Wales later holds is King. Typically, the Prince of Wales is the title given to the heir apparent of the British throne, meaning that this individual is first in line to become king. Upon the passing or abdication of the reigning monarch, the Prince of Wales ascends to the throne and is officially titled King. This progression underscores the lineage and hierarchy within the British monarchy, where the Prince of Wales represents the future leader of the country.

Other titles like Duke, Emperor, or Count are not standard titles that a Prince of Wales would necessarily hold as they ascend to the throne. While dukes are common within British nobility and emperors denote rulers of vast empires, they don't reflect the direct succession line to the British monarchy. Similarly, the title Count, which is used in various European countries, does not apply to the British royal system in the same way. Thus, the transition from Prince of Wales to King is a significant aspect of royal succession in the United Kingdom.