1900s–1940s
- 1901, 6 September: American President William McKinley was assassinated by anarchist Leon Czolgosz.[17]
- 1904, 18 May: Ion Perdicaris and Cromwell Varley kidnapped and ransomed by bandit Mulai Ahmed er Raisuli in Morocco.[18]
- 1904, 16 June: Governor-General Nikolai Ivanovich Bobrikov was assassinated in Senate House in Helsinki by Finnish nationalist Eugen Schauman.[19]
- 1906: Anarchist Mateu Morral, threw a bomb concealed in a bouquet to the passing carriage of King Alfonso XIII of Spain and his wife Victoria Eugenie of Battenberg on the day they were married. The royal couple were unharmed, but 24 people died in the incident.
- 1908, 1 February: The Portuguese King Carlos was murdered with his son Prince Luís Filipe, Duke of Braganza, by two men connected with Carbonária, a terrorist organisation linked with the Portuguese Republican Party.
- 1908, 13 July: The Amalthea Bombing. 1 killed and 23 injured in attack on strikebreakers by the young socialist activist Anton Nilsson.[20]
- 1909, 26 October: Assassination of Japanese Prime Minister Ito Hirobumi by Korean independence activist An Jung-geun.[21]
- 1910, 1 October: A bomb at the Los Angeles Times newspaper building in Los Angeles, California, United States, killed 21 workers.
- 1914, 28 June: Assassination in Sarajevo of Franz Ferdinand, Archduke of Austria and his wife, precipitating World War I.[22]
- 1915, 1 January: Battle of Broken Hill - Terrorists from the British colony of India (modern day Pakistan) shot at civilians in the Australian town, killing six.[23]
- 1915 2 July Frank Holt, (a.k.a. Erich Muenter) a German professor, exploded a bomb in the reception room of the U.S. Senate. The next morning, he tried to assassinate J.P. Morgan, Jr. (son of the financier whose company served as Great Britain’s principal U.S. purchasing agent for munitions and other war supplies), in a bid to stop the United States entering World War I against Germany.[24]
- 1920, 16 September: Wall Street Bombing killed 38 people and wounded 300 others.[25]
- 1921, March: A bomb attack by anarchic activists kills 21 people and wounded 80, in a theatre in Milan, Italy.[26]
- 1922, 16 December: Eligiusz Niewiadomski, a National Democracy sympathizer, shoots the first President of Poland Gabriel Narutowicz five days after his election.[27]
- 1925, 16 April: St Nedelya Church assault killed 150 people, mostly high-ranked individuals, and wounded 500 in the Bulgarian capital Sofia.[28][29]
- 1927: The Ku Klux Klan launched a wave of political terror in Alabama.
- 1927, 18 May: Andrew Kehoe wires the Bath Consolidated school with explosives. The resulting explosion killed 41 people. Kehoe then fired a round from his rifle into the front seat of his vehicle which was wired with dynamite. Kehoe and two other people were killed by the explosion.
- 1931, 29 August: Tadeusz Hołówko, a pro-Polish-Ukrainian unity activist, is assassinated by two members of the Organization of Ukrainian Nationalists[30]
- 1933, 10 October: A Boeing 247 was destroyed in midflight by a nitroglycerin bomb. All seven people aboard were killed. This incident was the first proven case of air sabotage in the history of aviation.[31]
- 1934, 15 June: Hryhoryi Matsyieyko, an OUN member, kills Bronisław Pieracki, the Minister of the Interior in the Polish regime.[32]
- 1934, 9 October: Assassination of King Alexander I of Yugoslavia and French Foreign Minister Louis Barthou in Marseille by Ustashas and IMRO.
- 1940 - 1956: George Metesky, the "Mad Bomber", placed over 30 bombs in New York City in public places such as Grand Central Station and The Paramount Theater, injuring ten during this period in protest against the local electric utility. He also sent many threatening letters.[33]
- 1946, 22 July: Bombing of King David Hotel, the British Military HQ in Jerusalem, by the Zionist group Irgun, with 91 deaths - a mix of military and civilian. [34]
- 1948 - Mahatma Gandhi assassinated by a Hindu extremist.