[3] In early 1515, he attended the Sapienza University of Rome, where he attained the degree of doctor of civil and canon laws, and received the Pope's blessing.

[1][3] In the summer of 1527, following the death of the Duke of Bourbon at the sack of Rome, he entered the service of Charles V, Holy Roman Emperor, working under Nicholas Perrenot, seigneur de Granvelle.

[1] He held the positions of councillor and master of requests by July 1527,[3] and at Valladolid on 25 June 1529, he was appointed Charles V's ambassador to England.

[3] He lived in Austin Friars, a neighbour to Thomas Cromwell ("Master Secretary" to King Henry VIII) in what later became Drapers' Hall.

[9] Chapuys' legal background made him an ideal candidate to defend the king's wife Catherine of Aragon, who was also an aunt of Emperor Charles V, against the legal proceedings, known at the time as the "King's Great Matter", which led eventually to the English rejection of papal authority and break from the Roman Catholic Church.

[10] Chapuys' attempts to defeat English machinations against Catherine eventually failed and Henry married Anne Boleyn.

He cultivated relationships with some of Mary's closest supporters, including Gertrude Courtenay, Marchioness of Exeter, who passed him information and secretly visited him in disguise.

[1] On his return, he worked to restore Anglo-Imperial relations and was involved in the negotiations for the alliance of February 1543, which led to Henry VIII and Charles V declaring war on France.

Davies, "His last known state paper is an acute analysis of the political situation" as Henry VIII was dying in January 1547.

[1] He was subsequently asked to recall his negotiations, and the previous attitude of the regime of Henry VIII, on the issue of the betrothal of Mary I.

[18][21] The death of his son ensured that the college and grammar school that he had founded would benefit from his vast fortune on his own demise.