Short answers, pulled from the story.
Eustace Chapuys was a Savoyard diplomat who served as Imperial ambassador to England from 1529 to 1545 under Holy Roman Emperor Charles V. He is best known for his extensive and detailed correspondence, which provides one of the most vivid firsthand records of Henry VIII's court. Hilary Mantel drew directly on his dispatches when writing her Wolf Hall trilogy.
Chapuys was appointed to defend Catherine of Aragon, an aunt of Emperor Charles V, against the legal proceedings known as the King's Great Matter. Catherine had specifically requested him because of his legal expertise and his proficiency in Latin. His efforts ultimately failed, and Henry VIII married Anne Boleyn.
Chapuys lived at Austin Friars in London, where he was a neighbour to Thomas Cromwell, Henry VIII's chief minister. He regarded Cromwell as a friend and cultivated a network of conservative courtiers as informants.
Chapuys founded the College of Savoy in Leuven in May 1548 for students from his native Savoy, and a grammar school in Annecy in December 1551. Only the gateway of the College of Savoy survives today and is now part of M, the city museum of Leuven. He also arranged in 1555 for his English pension to fund a scholarship at Leuven for English students.
Chapuys has a prominent role in all three novels of Mantel's Wolf Hall trilogy: Wolf Hall, Bring Up the Bodies, and The Mirror and the Light. Mantel used Chapuys's real-life dispatches to shape readers' perceptions of court events. He was played by Mathieu Amalric in the first television adaptation and by Karim Kadjar in Wolf Hall: The Mirror and the Light.
Eustace Chapuys died on the 21st of January 1556 and was buried in the chapel of the College of Savoy in Leuven. A portrait of him, believed to be contemporary, is held at the musee-chateau d'Annecy in Annecy, the city of his birth.