“The improvement of the British breed is my aim in life,” Winston Churchill wrote to his cousin Ivor Guest on 19 January 1899, shortly after his twenty-fifth birthday. Churchill’s view was reinforced by his experiences as a young British officer serving, and fighting, in Arab and Muslim lands, and in South Africa. Like most of his contemporaries, family and friends, he regarded races as different, racial characteristics as signs of the maturity of a society, and racial purity as endangered not only by other races but by mental weaknesses within a race. As a young politician in Britain entering Parliament in 1901, Churchill saw what were then known as the “feeble-minded” and the “insane” as a threat to the prosperity, vigour and virility of British society.'
https://www.winstonchurchill.org/pub...nd-eugenics-1/