The arms are those of Ponsonby impaling Cavendish, for the Hon. John Ponsonby (1713-1784) and his wife, Lady Elizabeth Cavendish (d. 1796) daughter of the 3rd Duke of Devonshire, whom he married in 1743. John Ponsonby was the second son of Brabazon Ponsonby, 1st Earl of Bessborough (1679–1758) and Sarah Margetson (d. 1773).
At this time in Ireland, a triple alliance of families known collectively as 'The Undertakers' effectively ruled Parliament, as the Viceroys spent little time in Dublin. These families were the Boyles, Beresfords and the Ponsonbys. John Ponsonby, the original owner of the present box was a prominent member of ‘The Undertakers’. He was always known, within the family as 'Speaker' Ponsonby, a nickname which signifies his prominent political position.
Ponsonby entered Parliament as M.P. for Newtown, co. Down in 1739. He was appointed Commissioner to the Revenue Board in 1742 and succeeded his father as 1st Commissioner in 1744. He was called to the Privy Council in 1748. In 1756 he was elected, by a large majority, as Speaker of the Irish House of Commons and re-elected in 1761 and 1769. He served six times as one of the Lords Justices of Ireland.
The author Francis Hardy, described Ponsonby’s manners as ‘exactly such as a parliamentary leader should have. Open, affable and familiar with a peculiar dignity of person, at once imposing and engaging.' (Francis Hardy, Life of Lord Charlemont, 1812, vol. 1 p. 193)
The presentation of the present gold box to John Ponsonby on 16 July 1756 is recorded in the Dublin assembly roll. Ponsonby’s father, Brabazon was presented with a gold box on the same day.
"Certain of the commons, praying to present their excellencies, James, earl of Kildare, and Brabazon, earl of Bessborough, two of the lords justices of this kingdom, as also the right honourable John Ponsonby, esquire, Speaker of the honourable House of Commons, with their several freedoms of this city in gold boxes. Granted accordingly, and that the expense of each gold box do not exceed thirty pounds, the same to be paid by the city treasurer, on the Lord Mayor’s warrant, and to be allowed him on his accounts." (Lady Gilbert. ed., ibid, p. 221).