Significant events that defined the life of Winston Churchill include his early military service during the Second Boer War and his political career through both World Wars. Churchill became the Prime Minister of the United Kingdom during World War II, where his leadership and stirring speeches rallied the British against Nazi Germany. His strategic insight and unyielding spirit during the Battle of Britain were pivotal in ensuring Allied resistance. Post-war, he played a crucial role in shaping international relations, coining the term “Iron Curtain” to describe the division between East and West during the Cold War.