The Big Four. The four most important leaders. They were Vittorio Orlando (Italy), Woodrow Wilson (US), David Lloyd George (Britain), and Clemenceau (France). Who were the leaders at the conference? British Prime Minister David Lloyd George, They were called the Big Four. The conference leaders also discussed a. The big four of the allied powers were. The British Empire; The Republic of France; The Kingdom of Italy; The United States of America. Due to. Where Francis Ferdinand was assassinated. President Woodrow Wilson strongly opposed many of these arrangements, including Italian demands on the Adriatic. On this day, Jack London, the illegitimate son of an astrologer father and a spiritualist mother, is born in San Francisco. Government signed the Treaty of Berlin on August 25, African American Athletes In Pursuit of Equity: Restored moral and supplies to the allies.