Overview
Duke of Rothesay is the main dynastic title traditionally given to the male heir apparent to the Scottish and, later, British thrones. The dukedom was created in 1398 by Robert III of Scotland for his eldest son.
Duke of Rothesay is the title mandated for use by the heir apparent when in Scotland, in preference to the titles Prince of Wales and Duke of Cornwall, which are used in the rest of the United Kingdom and overseas. The title is named after Rothesay on the Isle of Bute, but is not associated with any legal entity or landed property.The Duke of Rothesay also holds other Scottish titles, including Earl of Carrick, Baron of Renfrew, Lord of the Isles, and Prince and Great Steward of Scotland.
The current holder of the title is William, Prince of Wales, and his wife, Catherine, is the current Duchess of Rothesay.
History
David Stewart, Duke of Rothesay, the son of Robert III of Scotland, first held the dukedom from its creation in 1398. After his death, his brother James, later King James I, received the dukedom. Thereafter, the heir apparent to the Scottish Crown held the dukedom; an Act of the Parliament of Scotland passed in 1469 confirmed this pattern of succession.
From Wikipedia (CC BY-SA 4.0).