Short answers, pulled from the story.
Henry Algernon Percy, 5th Earl of Northumberland, was an English nobleman born on the 13th of January 1477 and died on the 19th of May 1527. He served at the courts of both Henry VII and Henry VIII, held major offices including Warden of the East Marches toward Scotland, and fought at the Battle of the Spurs in 1513.
The Northumberland Household Book is a detailed record of the 5th Earl of Northumberland's household management, begun around 1512 and focused mainly on his Yorkshire residences at Leconfield and Wressle. It is one of the few surviving household accounts from a non-royal establishment of the period, recording the earl's income of about two thousand three hundred pounds a year and his annual expenditure of no less than fifteen hundred pounds on servants and retinues.
Northumberland spent no less than fifteen hundred pounds a year on servants and followers, out of an annual income of roughly two thousand three hundred pounds. The remaining funds had to cover court travel, building projects, and a lifestyle described as extraordinarily magnificent, leaving him in debt despite being one of the richest magnates of his day.
At the Battle of the Spurs, Henry Percy the 5th Earl of Northumberland commanded the "showrers and forridors" - Northumberland men riding light geldings who carried out reconnaissance and flanking duties. He served in the 1513 war as a grand captain with a very large retinue, joining the campaign from Calais through the siege of Thérouanne.
Henry Percy the 5th Earl of Northumberland was buried at Beverley Minster in the Percy Chapel, where he had built a splendid shrine. His tomb monument was recorded in the Wriothesley Heraldic Collections, now preserved in the British Library in London.
Two of his three sons died violently in the late 1530s: Sir Thomas Percy was executed in 1537 for participating in the Pilgrimage of Grace, and Sir Ingelram Percy died imprisoned in the Tower of London in 1538 after also taking part in the uprising. His eldest son became the 6th Earl of Northumberland, and his daughter Lady Margaret Percy's monumental brass survives in Skipton Parish Church in Cumbria.