John Russell, 6th Duke of Bedford (6 July 1766 - 20 October 1839) was a younger son of the Marquess of Tavistock (eldest son and heir of the 4th Duke of Bedford who had died during the lifetime of his father). At the time of his birth, Lord John Russell (as he then was) was not expected to succeed to the title - unless his elder brother Francis Russell, Lord Howland died in infancy or at some point later without legitimate heirs.
Lord John Russell married relatively young, to the Honourable Georgiana Byng, a daughter of the 4th Viscount Torrington. They had three sons before she died young. His life then changed suddenly when his elder brother the 5th Duke of Bedford died suddenly without marrying or fathering any legitimate sons in 1802. At his death, the 5th Duke was reportedly engaged to Lady Georgiana Gordon, youngest daughter of the formidable matchmaker, the Duchess of Gordon. [Three other daughters were married to the 4th Duke of Richmond & Lennox, the future Duke of Manchester, and the future 2nd Marquess Cornwallis at this time].
After a suitable period, the new 6th Duke married (as his 2nd wife) Lady Georgiana Gordon. The new Duchess was unhappy that her husband already had three sons, which meant that any son of hers would be unlikely to succeed to the dukedom and associated properties. In later years, the marriage is said to have entirely broken down, but not before they had produced several children including Lady Louisa Jane Russell who, along with her cousin Lady Cecilia Gordon-Lennox, is an ancestress of the late Diana, Princess of Wales.
Like most of the Russells, Bedford was a Whig in politics, and served as Lord Lieutenant of Ireland in the Whig government of 1806-1807.
The 6th Duke's second son Lord John Russell, later the 1st Earl Russell, a 19th century prime minister, is probably his most distinguished descendant, along with the latters' grandson the philosopher Bertrand Russell (the 3rd Earl Russell).
At his death, the 6th Duke was succeeded by his eldest son (by his first wife) as Francis Russell, 7th Duke of Bedford. The title remains among his descendants.