Royal Visit to the USA

[MacMillan of Rathdown]

Although that is currently the announced plan, it is not by any means a given.

Prince Charles, as Prince Philip's eldest son, will inherit the title.

Possibly, but that is by no means a given. All royal titles revert to the sovereign, who then determines what, if any, destination of that title will be allowed.

When Charles becomes King the title Edinburgh will merge in the Crown. It will be up to Charles or his heir William to issue Letters Patent to create a second Duke of Edinburgh for Edward. The alternative is that Charles refuses and Edinburgh becomes one of the subsidiary titles of the Heir Apparent.

This line of argument presupposes that (1) the present Duke of Edinburgh outlives Her Majesty, and (2) that the letters patent creating HRH Prince Edward Duke of Edinburgh have not already received Royal Assent. As it was announced at the time when HRH Prince Edward received the title of Earl of Wessex that he would succeed his father as Duke of Edinburgh; I suspect, as they say in Ireland, that "the fix is in".