When Prince Harry and Meghan stepped back as working royals, one of the conditions on which they forged their independent lives was that they would retain their HRH titles but not use them. Standing for His or Her Royal Highness,

When Prince Harry and Meghan stepped down as working royals there was an agreement to stop using HRH, which stands for Her/His Royal Highness, but they still hold the titles. Sources close to the California-based couple reject that this card was a breach of the agreement struck on their departure from royal duties.

Since it emerged that Meghan Markle sent a gift basket to a friend with a card that described her as 'HRH The Duchess of Sussex' controversy has grown - now a constitutional expert has weighed in