With the arrival of Kate and William on the Isle of Mull today, you may be hearing references to the "Lord of the Isles" in Scotland.
The pair, who are next in line to become King and Queen, hold the ancient title, something that can trace its origins back to the 12th century.
What is the Lordship of the Isles in Scotland and why do Kate and William hold this title?
The Lordship of the Isles traces its roots back to the Norse-Gaelic rulers of the Western Isles and the Isle of Man (Image: PA) The Lord of the Isles title traces its roots back to the medieval period and was originally held by the Norse-Gaelic rulers of the Isle of Man, Argyll, as well as the islands of Scotland.
At its height, the semi-independent power controlled large parts of western Scotland and wielded an extremely powerful navy, making its rulers the most powerful lords after the monarchs of Scotland and England.
For much of its history, the title was held by the MacDonald clan before these lands were seized by King James IV of Scotland in 1493.
Since then, the title has mostly been borne by the heir apparent to the King of Scots, a title that, after the Act of Union of 1707, has been held by the Prince of Wales.
This means the title is currently held by Prince William, the Prince of Wales and Duke of Rothesay.
William and Kate have been married for around 13 years, having tied the knot in 2012 (Image: PA)