He became heir apparent to the dukedom in October 1995, when his uncle Henry, 11th Duke of Northumberland, died.

Percy's parents, now Duke and Duchess of Northumberland, were eager to protect him from "vices and pitfalls", and they filed a lawsuit to prevent him from inheriting £1 million and a £350,000 annual income upon turning 18.

[1] At the age of 12, Percy served as a page of honour to Elizabeth II at the 1996 State Opening of Parliament.

Percy was educated at Eton College,[2] then studied geography at the University of Edinburgh, specialising in sustainable development and renewable energy.

Percy studied Arabic language at the University of Damascus, and later worked on development projects in the Middle East, including Abu Dhabi.