Bellenden's duties included meetings with English border officials. A letter written by the English deputy border warden
William Eure to
Thomas Cromwell on 26 January 1540 describes a meeting with Thomas Bellenden at
Coldstream in January 1540. Eure said that Bellenden was over fifty years old. Bellenden described the performance of an interlude at
Linlithgow Palace before James, his wife
Mary of Guise and his bishops and council on the feast of the Epiphany. The play concerned the reformation of the church, and Eure obtained a more detailed description from a Scottish contact who saw the play at Linlithgow. This description corresponds with the expanded later text of
David Lyndsay's play
A Satire of the Three Estates. Eure talked with Bellenden about the possibility of a
Reformation of the 'spirituality' in Scotland. The play at Linlithgow had shown the 'naughtiness' of the church. Bellenden said that after the play the King spoke to the churchmen in the audience asking them to reform their factions and manner of living, otherwise he would send six of them into England to his uncle,
Henry VIII. Bellenden said that James V intended to expel clergymen from royal appointments and he asked Eure to send him secretly copies of the English statutes that
suppressed the Roman Catholic religion.
John Knox mentioned Thomas Bellenden positively in connection with the regrets of his predecessor as Justice Clerk, Thomas Scott of Pitgorno. Knox also wrote that Bellenden helped
Regent Arran to power but his influence was lost when Arran abandoned the plan for
Mary, Queen of Scots to marry
Prince Edward of England. Bellenden had family connections with the royal court and literature. At the end of his life he copied the
Eneados, a translation of
Virgil's Aeneid by
Gavin Douglas into a manuscript now kept at
Lambeth Palace. He co-signed the manuscript, "Heir ends the buke of Virgill written by the hand of Johanne Mudy with Mr Thomas Bellenden of Auchinnoull Just. Clerke and endit the 2 Febrii Annorum xlv." ==Ambassador to Henry VIII==