Courtier
On 6 November 1515, he was appointed Master of the Horse, with a salary of £40 a year, an appointment which he surrendered seven years later in favour of Sir Nicholas Carew. On the same day he had an annuity of fifty marks granted to him as squire of the body. In the same year he became an executor of Sir Thomas Cheney of Irthlingborough, Northamptonshire, and before Christmas was writing to a minstrel in the Low Countries named Hans Nagel, to allure him over to England as a spy who could make reports about the fugitive, Richard De la Pole.
In 1519, he received two letters from Erasmus in praise of the court of Henry VIII. Next year he attended the king as Master of the Horse to the Field of the Cloth of Gold, and also to the meeting with the Emperor Charles V at Gravelines. On 12 February 1521 he had a grant of the custody of the manor of Leeds in Kent, and of the lordship of Langley, near Maidstone, for forty years.
In May 1521, he was one of the justices both in Kent and in Surrey before whom indictments were found against Edward Stafford, 3rd Duke of Buckingham. Next year, on 24 April, the duke's manor of Hadlow in Kent was granted to him. In the autumn of 1521 he accompanied Thomas Wolsey to the Calais conferences, but on 21 September Richard Pace wrote to the cardinal to send him and Francis Brian home, as the king had few to attend him in his privy chamber.
In May 1522 he went again in Wolsey's train to meet the emperor at his landing at Dover. In 1522, after surrendering his post as master of the horse, he was appointed Comptroller of the Household.
In 1523, he became, on the return of Gerald FitzGerald, 9th Earl of Kildare to Ireland, one of the earl's sureties that he would come again on reasonable warning and present himself before the king. On 1 September on the death of his uncle Nicholas Vaux, 1st Baron Vaux of Harrowden, Guilford and three other executors received orders to deliver up Château de Guînes to Lord Sandes.
At this period his personal wealth was growing with many grants, and about this time he is said to have surrendered his office of standard-bearer, which was conferred upon his brother, Sir Edward, in conjunction with Sir Ralph Egerton. He took on administrative duties, such as Chamberlain of the Exchequer from 1525. In 1526, he was invested as a Knight of the Garter.
About 1527, he and the poet Sir Thomas Wyatt built a banqueting-house for the king at Greenwich. He then accompanied Cardinal Wolsey on a diplomatic mission to France, and was acknowledged by Francis I as an ambassador. He was actually receiving at this time a pension from Francis under the treaty of the Moore.
In the spring of 1528 there were seditious rumours in some parts of Kent about demanding repayment of the loan which the people had been forced to contribute to the king; and some even proposed to break into gentlemen's houses, among others that of Guildford's half-brother, Sir Edward, and steal their weapons. This gave Sir Henry much to do, and he ultimately sat on a commission at Rochester for the trial of the malcontents. When Thomas Cromwell came as Wolsey's agent to suppress the small priories in Kent for his college at Oxford, Guildford asked him to visit him at Leeds Castle, with a view to obtaining from him the farm of the suppressed house of Bilsington.
