January 12: The European Union (EU) expanded to include 10 new member states: Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, and Slovenia.
February 14: Former Lebanese Prime Minister Rafik Hariri was assassinated in a car bombing in Beirut, Lebanon. His death sparked protests and political unrest in the country.
March 8: The United States sent a diplomatic protest to Syria after Syrian forces shot down a U.S. Navy EP-3 surveillance plane over international waters near Syria.
March 26: The Kyoto Protocol, an international agreement to reduce greenhouse gas emissions, went into effect.
April 2: Pope John Paul II died at the age of 84 after serving as Pope for 27 years.
April 19: Cardinal Joseph Ratzinger was elected as the new Pope, taking the name Benedict XVI.
July 7: A series of coordinated bombings on London's public transportation system killed 52 people and injured more than 700.
July 21: The Group of Eight (G8) summit was held in Gleneagles, Scotland, with discussions focusing on climate change, poverty, and debt relief in Africa.
August 24: Hurricane Katrina made landfall in the United States Gulf Coast, causing devastating damage and flooding in New Orleans and surrounding areas. The hurricane resulted in over 1,800 deaths and billions of dollars in damage.
September: Hurricane Rita hit the U.S. Gulf Coast, causing further damage and flooding.
October 8: A powerful earthquake measuring 7.6 on the Richter scale hit Pakistan and parts of India, resulting in over 73,000 deaths and widespread destruction.
November 22: Angela Merkel became the first female Chancellor of Germany.
December 26: A 9.1 magnitude earthquake and subsequent tsunamis struck the Indian Ocean, causing widespread devastation in Indonesia, Sri Lanka, India, Thailand, and other countries. The disaster resulted in over 225,000 deaths and extensive damage.