His official life and high qualifications are thus summed up by the Duc de St. Simon – ‘Ruvigny was a good but plain gentleman, full of sense, wisdom, honour, and probity; a strong Huguenot, but of eminent administrative powers, and great dexterity. These qualities, which had gained him great reputation among those of his religion, had procured him many important friends and much consideration in the world. The ministers and the principal nobles reckoned him as a friend, and were not indifferent to the circumstance being known that he reckoned them as his friends, and the most influential magistrates were eager to be so also. Under a very plain exterior, he was a man who knew how to ally straightforwardness with finesse, in his designs and arrangements. Yet his fidelity was so well known, that he had secrets and deposits confided to him by the most distinguished persons. For a great number of years he was the Deputy at court of his religion; and the King (of France) often availed himself of the connections his religious creed gave him in Holland, Switzerland, England, and Germany, for secret negotiations in those countries, where he served him very usefully.’
The marquis was not formally an ambassador. However, he was constantly with King Charles, whom he advised to satisfy his parliament by clearing himself of the imputation of Popish leanings. Charles blamed the Duke of York, and said, ‘I could get over all such difficulties, were it not for la sottise de mon frere’. Ruvigny reported to Louis the following disagreeable truths in 1676: ‘The King of England is in a manner abandoned by his ministers, even the most confidential. The Duke of York is entirely in your Majesty’s interest. All England is against your interests; and there is only the King and Duke of York who embrace them with affection.’ Ruvigny spent two years in England. The result of his English embassy was that France agreed that Charles should be the mediator of a peace with Holland.
It is not a pleasing thought that the Marquis should have been an ambassador of Louis XIV, whose most frequent scheme was to make dishonourable pensioners of the Kings and public men of other countries. That the business of diplomatic artifice was inconsistent with Ruvigny’s professions as a Bible-loving Protestant, his friend Burnet insinuates. The Bishop calls him “a man of great practice in business and in all intrigues,” and says: “He was still a firm Protestant, but in all other respects a very dexterous courtier, and one of the greatest statesmen in Europe.” (From: Henri de Ruvigny, Earl of Galway by David C.A. Agnew (1864))