Just like her sister-in-law Kate Middleton, Meghan Markle will be making the transition from commoner to royal with a new title.
She is tipped to become the first Duchess of Sussex.
By tradition, male members of the royal family receive a title from the monarch on their wedding day, andthe vacant title Duke of Sussex is regarded as the most likely choice for the Prince.
The only previous Duke of Sussex was married twice, but neither of his marriages was approved by his father, George III, meaning they were considered unlawful.
A dukedom is the highest rank in the British peerage and comes from the Latin word dux, meaning leader.
The five titles from highest to lowest are: duke, marquess, earl, viscount and baron.
For women, they are: duchess, marchioness, countess, viscountess and baroness.
The Queen is expected to choose a Dukedom for her grandson from titles that are currently suspended. Other options include the dukedoms of Clarence, Connaught, Windsor, Albany, Cumberland and Teviotdale.
However, many of them have inauspicious histories that would almost certainly rule them out.
Charles Kidd, editor of Debrett's Peerage & Baronetage, said he believed the Queen would choose the Dukedom of Sussex for Prince Harry, which was previously held by George III's sixth son Augustus Frederick.
When Prince Harry's brother William married Catherine Middleton in 2011, the Queen bestowed the title of the Duke of Cambridge, Earl of Strathearn and Baron Carrickfergus on her grandson. Catherine, known as Kate, became the Duchess of Cambridge.
