What is Prince Charles, the Queen's eldest son, also known as?

The title "Prince of Wales" has a long and fascinating history, dating back to 1301. Edward I, the English king, wanted to appease the Welsh after conquering Wales. He promised them a prince "born in Wales, who spoke no English." He then presented his own newborn son, Edward II, who fit the description perfectly! Since then, the title has traditionally been given to the heir apparent to the British throne. It's a symbolic title, connecting the future monarch to the history and traditions of Wales. While Prince Charles also holds other titles, like Duke of Cornwall, the Prince of Wales is the title specifically associated with being next in line to the throne. The Duke of Edinburgh title belonged to Prince Philip, the Queen's husband, and has no connection to the heir. "King of Ireland" is incorrect because Ireland is an independent republic, and "Commonwealth King" is not a recognized title within the British monarchy. So, the Prince of Wales is the correct answer because it's the established title for the heir apparent.