The Gentleman's Magazine was an important and influential monthly magazine in the 18th and 19th Centuries; it began in 1731, ceased regular publication in 1907, and shut down completely in 1922.
The Supplement for 1809 carried a brief description — rather snarky — of the residence and life of the recently deceased Marquis of Lansdowne. Here is what the anonymous author has to say about the Marquis' favorite pastime:
His Lordship's chief delight [was] in driving four foresters, whose size not much exceeds that of the Newfoundland dog.
The author concludes by unfavorably comparing the late Marquis to his father: "how the son degen'rates from the sire." This recently deceased Marquis was
John Henry Petty, Earl Wycombe (6 December 1765 – 15 November 1809), the 2nd Marquess of Lansdowne. His "sire," William Petty Fitzmaurice (2 May 1737 – 7 May 1805), the 1st Marquess of Lansdowne and also known as the Earl of Shelburne, was Prime Minister of Great Britain from 1782 - 1783.
The slightly snarky tone of this remark may well be due to the fact the 2nd Marquess was often critical of the the conservative government of Britain which was in power for much of his adult life; he was also a supporter of Irish and American independence, and disdainful of organized religion.
A "forester," by the way, is a breed of native British pony now known as the New Forest pony, a breed with ancient roots. More at Wikipedia.