[1] Sackville was first recorded as a cricketer in 1734 when he and his brother, Lord Middlesex, played for a Kent side against one from Sussex at Sevenoaks Vine.
[7] The couple's parents were furious, and the Prince of Wales compensated Sackville for any loss of income, making him a lord of his bedchamber in 1745, and thus securing him as a recruit to his party.
[11][8] Finally, he was committed to a private lunatic asylum circa 1746, then sent abroad to exile on a very small allowance in Lausanne where Lord Shelburne met him in 1760, and commented on his dirty condition but lucid conversation.
[8] According to his descendant Robert Sackville-West, 7th Baron Sackville in his book Inheritance he became insane later in life, dying in Geneva, Switzerland, aged 52.
However, his brother lived long enough to allow John Philip's son to inherit his title and become the next Duke of Dorset.