If you’ve ever been on Twitter during a “what is Kate’s last name” debate, you know to stay far, far away from that fire. For whatever reason, the most hotly debated topic is Kate’s official title. On her wedding day, Catherine received a royal title befitting of her new royal status as the wife of Prince William, the Duke of Cambridge, Earl of Strathearn, Baron of Carrickfergus. Since then, she was no longer Kate Middleton, but rather Catherine, the Duchess of Cambridge, Countess of Strathearn, Baroness of Carrickfergus.
The Duchess of Cambridge
When Kate married William, she became the Duchess of Cambridge. This is her main royal title and is used most often when in England and abroad on royal tours.
The Dukedom of Cambridge was first used as a peerage in 1664. Over the next three centuries, “Cambridge” would become an earldom and marquessate as well. The Cambridge title has been held by many future monarchs and high profile royals, including George II and Edward IV.
The title was – somewhat obviously – named after the city of Cambridge, which has been around since before Roman times. The town holds great prestige due to its long history, rich culture, and iconic university.
The Countess of Strathearn
Kate’s title when she is in Scotland is the Countess of Strathearn. Since she will one day be the queen consort of Scotland, it is custom for heirs and their spouses to take on a “Scottish title” representing a region of the country. Prince William is the Earl of Strathearn and Catherine is the Countess of Strathearn.
The first recorded Earl of Strathearn lived around 1138. The earl was the provincial leader of the district of Strathearn. It was not used as an official royal peerage until the 16th century.
According to the Strathearn website: “Strathearn straddles both the Scottish Highlands and Lowlands – glens, lochs, mountains and open spaces to the north – rich farmland and towns on the lowlands to the south. This was originally one of Scotland’s ancient Celtic Earldoms, with the title Earl of Strathearn, however the title expired and the lands became used for royal hunting from the 12th Century. “
The Baroness of Carrickfergus
When Catherine is in Northern Ireland, which is a province of the United Kingdom, she is called Lady Carrickfergus. The title is officially styled as “Baron Carrickfergus” for William and “Baroness Carrickfergus” for Catherine.
The title did not come into the history books until the mid-19th century, when it was bestowed upon the 3rd Marquess of Donegal. He was the only person to have been given the title, having died in 1883 with no heirs, until Prince William was given the peerage upon his marriage.
Carrickfergus is the oldest town in Country Antrim, with its history dating back to the 12th century. The town boasts a gorgeous Norman castle and picturesque marina and waterfront. It has had many touches with fame despite its unknown status, including acting as a dock for the Titanic and being the ancestral home of Andrew Jackson.
But is Kate a Princess?
Technically, yes. Kate is married to Prince William which does, technically, make her a princess. However, she is NOT Princess Kate. She is “Princess William.” The reason why is a complicated, confusing explanation including bloodlines, heirs, birthrights, and antiquated laws. She is a princess because she is married to a prince, similar to when Bridget marries Mark Darcy, she becomes a Darcy.
So what’s her last name?
She does not have one. Period, no ifs, ands, or Middletons. As a married woman, Kate renounced her maiden name and took the name of her husband. Since Prince William – as a royal – does not have a last name, neither does Kate. When it is absolutely, positively required (which it hardly ever is), Catherine may use the name “Cambridge” or “Windsor.” These are not her surname, but names that she uses in place of a surname.
In the future…
When Charles, the Prince of Wales, becomes sovereign, the Duke and Duchess of Cambridge will be given the title Prince and Princess of Wales, the Duke and Duchess of Cornwall. Their titles (Cambridge) will return to the “title bank” for later use. When this happens, they will likely be called Prince William and Princess Catherine. Kate’s title will most likely be Catherine, Princess of Wales, Duchess of Cornwall, followed by her other granted titles. Eventually, Catherine will become queen consort and everyone who called her “Waity Katie” will eat their words.
When Charles becomes King, William does not automatically become Prince of Wales, nor does he lose any of his existing titles.
William does automatically become Duke of Cornwall as he would be the eldest son and heir apparent to the throne (both criteria must be met to receive this title).
So he becomes HRH The Duke of Cornwall and Cambridge. But he’ll be known as D of Cornwall. Catherine is HRH Duchess of Cornwall.
And its Prince George of Cornwall and Princess Charlotte of Cornwall.
As heir apparent he also becomes (wait for it..) Duke of Rothesay, Earl of Carrick, Baron Renfrew, Lord of the Isles, Prince and Great Steward of Scotland.
When he becomes Prince of Wales is up to The King. Time lag varies historically but poss 6 months. Catherine becomes HRH The Princess of Wales, with Prince George of Wales and Princess Charlotte of Wales.
When William becomes king, that is when all his titles revert to the Crown.
KIng William V
Queen Catherine
PRince George, Duke of Cornwall. (Eventually Prince of Wales)
PRincess Charlotte.
Simple really
I don’t think that Catherine is anywhere in her title. To use Catherine, Duchess of Cambridge or in the future Catherine, Princess of Wales would be using the style of a divorcee. I remember when Charles and Diana got divorced, she went from being HRH The Princess of Wales to Diana, Princess of Wales.
Hi Melissa, this is a tricky question! Her name is not a part of her official title but it is part of her official name – if that makes sense! In your example with Diana, the difference was the word “the.” Diana was technically Her Royal Highness, Diana, the Princess of Wales and after her divorce she was just Diana, Princess of Wales. A clearer example is with Sarah Ferguson. During her marriage, she was Sarah, the Duchess of York and today she is just Sarah, Duchess of York.
Didn’t they use Mountbatten-Windsor on the wedding certificate?
William and Catherine’s wedding certificate was never released and they did not use that name on George’s birth certificate. A bit of research shows that when then-Princess Elizabeth married Prince Phillip, she used the name Windsor and he Mountbatten. When Charles married Camilla in 2005, Charles did not use a surname.
I’ve always wondered…what is the last name used when booking flights? Cambridge?
They will often use fake names (Jones, Smith – even Middleton!). Since they don’t exactly go through TSA ID checks, they don’t have to worry about their name matching their passport!
This explains so much. Thank you!
So happy with this post! It irks me when she is referred to as “Princess Kate.” It just shows a lack of respect. Thank you for researching and writing this!
Question: So technically Camilla is the current Princess of Wales. Does she not go by that title out of respect for Diana or does she just not prefer it?
Hi Sarah! My understanding is that Camilla is technically the Princess of Wales. She is married to the Prince of Wales and is the next Queen Consort. According to the Prince of Wales’ website “Upon her marriage to The Prince of Wales, Her Royal Highness decided to use the title The Duchess of Cornwall, as her husband is also known as The Duke of Cornwall. When in Scotland, Her Royal Highness is known as The Duchess of Rothesay.” This leads me to believe she is the Princess of Wales but chose not to use the title officially or publicly.
But, when William is king, what will Catherine be styled as?
Hi Julia! Assuming Kate takes a similar consort title as Queen Elizabeth The Queen Mother, Catherine will be titled “Her Majesty The Queen” and will be called “Queen Catherine.”