1901: Queen Victoria's death marked the end of the Victorian Era in the United Kingdom. Her son Edward VII succeeded to the throne, introducing the Edwardian Era.
1903: The Wright Brothers made the first successful powered airplane flight at Kitty Hawk, North Carolina in the United States, pioneering the era of aviation.
1905: The Russo-Japanese War ended with the Treaty of Portsmouth, marking a significant geopolitical shift in East Asia with Japan emerging as a major power.
1910: The Halley's Comet was visible from Earth, captivating astronomers and the general public with its remarkable appearance.
1912: The Titanic, considered the unsinkable ocean liner, tragically sank after hitting an iceberg in the North Atlantic Ocean during its maiden voyage, resulting in a significant loss of life and leading to reforms in maritime safety.
1914: World War I began, involving major European power in a global conflict that would reshape the political and territorial landscape of the world.
1915: The Armenian Genocide took place during World War I, involving the systematic killing and deportation of Armenian people by the Ottoman Empire.
1917: The Russian Revolution led to the overthrow of the Romanov Dynasty, establishing the Bolshevik Party under the leadership of Vladimir Lenin and the creation of the Soviet Union.
1918: World War I ended with the signing of the Armistice agreement, bringing an end to the devastating conflict that involved millions of loss lives and extensive destruction.
1919: The Treaty of Versailles marked the official end of World War I, imposing harsh penalties on Germany and its allies, leading to resentment and setting the stage for future conflicts.
1920: The first Summer and Winter Olympic Games took place in Antwerp, Belgium, and Chamonix, France, respectively, marking the revival of the ancient Greek athletic tradition and the international sports competitions.
These events had profound and lasting impacts on various aspects of society, including geopolitical dynamics, technological advancement, social and political movements, the arts, and literature.