When Elizabeth II dies, her Heir Apparent for some 71 years becomes King immediately with her last breath.
There is one thing Royal Family followers don’t want to think about and that’s saying goodbye to Britain’s longest-reigning monarch. Unless something unusual happens, Prince Charles will ascend the throne upon the death of his mother, The Queen. It is considered unlikely that the Queen will abdicate.
Prince Charles has been treated poorly by the press, who fell in love with Princess Diana, and needed a bad guy in that unfortunate divorce. Remember that no divorce is completely one-sided, even among royalty. Charles is a fairly quiet and reserved man, reasonably serious, but with a strong sense of humor that he keeps well hidden these days.
For anyone else to become king before him, he would either have to die, or the British Parliament would have to change the law. Parliament, through its legal authority as encapsulated in the Succession to the Crown Act 2013, decides how the succession process works. This is in keeping with previous Acts of Parliament, such as the Bill of Rights 1689 and the Act of Settlement 1701, as well as the Royal Marriages Act 1772. These dictate who is allowed to succeed, who is disqualified, and the order of succession.
The Succession to the Crown Act 2013 was a complicated piece of legislation, because it had to be co-ordinated across all the Commonwealth countries where the British monarch is also head of state, currently about 15 other nations. The Act commenced in 2015, after equivalent legislation was in place in all the other relevant Commonwealth nations. As a result, the succession to the crown, and so head of state, is the same in all Commonwealth countries, which avoids potential problems in future years.
The major changes in the 2013 Act were that marriage to a Catholic no longer removed one from the line of succession (but being Catholic still does, as the monarch is also head of the Church of England), and that rather than all the male children of the sovereign having a higher priority in the line of succession, the sovereign’s children are now ordered by birth order, not gender. The gender change is not retrospective, but the ‘marrying a Catholic’ is. There were some other important things as well, but those are the main two that affect the succession. This is now universal across the Commonwealth, as per the 2011 Perth Agreement.
Assuming Prince Charles outlives the Queen, he will become king, although he may not necessarily be King Charles III, as he can chose a different regional name.
After Prince Charles’ death, his elder son, Prince William, will succeed to the throne, followed by his children in birth order.
The monarchy is not a popularity contest, nor is it an elected position. The monarch is above all that, and does not answer to popularity contests or the electorate’s current whims. The monarch embodies the nation, and so must do what is right for the nation, despite everything else that may arise. In old-fashioned language, the monarch answers only to God for the nation that has been placed in their care. The Queen has done an admirable job of accomplishing this, and has made sure that Prince Charles has been trained in what is required to continue this role.
I have no doubt that he will make a very good job of king, and we may well regret that his reign was relatively short when it ends.