1. World War I (1914-1918):
- The assassination of Archduke Franz Ferdinand of Austria triggered a chain of events leading to the outbreak of war.
- Major battles included the Battle of the Somme (1916), the Battle of Verdun (1916), and the Battle of Passchendaele (1917).
- The war ended with the armistice signed between Germany and the Allied Powers on November 11, 1918.
2. World War II (1939-1945):
- The invasion of Poland by Germany on September 1, 1939, marked the beginning of World War II.
- Notable events include the Battle of Britain (1940), the attack on Pearl Harbor (1941), the Battle of Stalingrad (1942-1943), and the D-Day landings in Normandy (1944).
- The war ended with the unconditional surrender of Germany in May 1945 and Japan in August 1945, following the atomic bombings of Hiroshima and Nagasaki.
3. The Korean War (1950-1953):
- The war began when North Korea invaded South Korea on June 25, 1950.
- The United States and other United Nations forces intervened to support South Korea, while China backed North Korea.
- The war ended with an armistice signed on July 27, 1953, dividing Korea along the 38th parallel.
4. The Vietnam War (1955-1975):
- The conflict started as a struggle between the communist North Vietnam and the anti-communist South Vietnam.
- The United States became heavily involved in the war, sending troops and providing military support.
- The war ended with the fall of Saigon to North Vietnamese forces in April 1975, marking the reunification of Vietnam under communist rule.
5. The Gulf War (1990-1991):
- The war began when Iraqi forces invaded and annexed Kuwait on August 2, 1990.
- A U.N.-authorized international coalition, led by the United States, launched a military operation against Iraq to liberate Kuwait.
- The war ended with the Iraqi defeat and the liberation of Kuwait in February 1991.
These wars represent a fraction of the many conflicts that have occurred throughout history. Each war had its own causes, consequences, and implications, leaving lasting impacts on the world.