Battle of Britain Day is observed in the United Kingdom every September 15, commemorating the significant contributions of the Royal Air Force during the Battle of Britain, which lasted from July 10 to October 31, 1941. This day marks the anniversary of the Luftwaffe's longest bombing attack against Britain, which engaged the entire Royal Air Force in defense of London and the South East. The observance honors the flying aces and their pivotal role in achieving a decisive victory for Britain, a turning point in World War II. Winston Churchill famously remarked about the pilots, stating, “Never in the field of human conflict was so much owed by so many to so few,” highlighting the gratitude felt by the nation. The day serves as a memorial to those who fought and is an important part of British history.