John Francis Stanley Russell, 2nd Earl Russell, known as Frank Russell, was a British nobleman, barrister and politician, the elder brother of the philosopher Bertrand Russell, and the grandson of John Russell, 1st Earl Russell, who was twice prime minister of Britain. The elder son of Viscount and Viscountess Amberley, Russell became well-known for his marital woes, and was convicted of bigamy before the House of Lords in 1901, the last peer to be convicted of an offence in a trial by the Lords before that privilege of peerage was abolished in 1948.

Bertrand Arthur William Russell, 3rd Earl Russell, was a British mathematician, logician, philosopher, and public intellectual. He had influence on mathematics, logic, set theory, and various areas of analytic philosophy.