Thursday, Feb. 22, 2024 at 8 p.m. on KPBS 2 / Stream now with KPBS Passport! On May 10, 1940, Winston Churchill became Prime Minister of the United Kingdom — and Germany launched its offensive against France and the Low Countries. British troops were evacuated from Dunkirk by June 4, delivered the “Finest Hour” speech on June 18, and in mid-July the Battle of Britain commenced.