Kate And William's Titles Are Different In Scotland. Here's Why
When Kate Middleton and Prince William aren't being referred to as simply "Kate and William," the royal couple is best known as the Duke and Duchess of Cambridge. However, they also have the titles Earl and Countess of Strathearn whenever they visit Scotland (via People).
According to Cambridge News, Kate and William received their titles Duke and Duchess of Cambridge from Queen Elizabeth. The titles come from the city of Cambridge, which is one of the six royal dukedoms. "Duke" and "duchess" indicate the highest rank below the Queen, and the titles were passed down from earlier heirs (via Mental Floss). Traditionally, the hierarchy indicated which people had the most political and landowning power in old Britain.
The highest-ranking members of the royal family, however, receive more than one royal title. As Express reports, Kate and William also received regional titles when they got married in 2011 (via Page Six). The titles Earl and Countess of Strathearn are meant to be used when the royal couple is in Scotland, particularly because Scotland has its own system of nobility (via Tatler).
Kate and William have special titles in Ireland, as well
According to Country Living, Kate Middleton and Prince William received the Scottish titles Earl and Countess of Strathearn because they met at St. Andrews University. Indeed, St. Andrews holds a special place in the hearts of the royal couple, who plan to visit the university during their mini, Royal Tour of Scotland this week (via Woman and Home).
However, Kate and William have another set of titles. In addition to being the Duke and Duchess of Cambridge and the Earl and Countess of Strathearn, the royal couple is also known as Baron and Lady Carrickfergus (via Country Living). Queen Elizabeth also bestowed these titles on Kate and William on their wedding day, and the royal couple is meant to use them whenever they visit Northern Ireland.
It's important to note that some of these titles may change if Prince Charles becomes the King of England. In this case, Prince William would likely inherit the title Prince of Wales, and Kate would be known as Catherine, Princess of Wales (via Woman and Home).