Dictators, including Adolf Hitler, Joseph Stalin, Napoleon and Kim Jong-un, reveal what happens when one person is given unchecked power. These autocrats ruled their countries - and often attacked and invaded others - using excessive force to wield absolute control.
As the successor to his father, Hafez, Bashar al-Assad has continued with his father's brutal rule of Syria.
Kim Jong-un became the supreme leader of North Korea in 2011, succeeding his father Kim Jong-il.
Joseph Stalin ruled the Soviet Union for more than two decades, instituting a reign of death and terror while modernizing Russia and helping to defeat Nazism.
Fidel Castro orchestrated the Cuban Revolution and was the head of Cuba's government until 2008.
Saddam Hussein was president of Iraq for more than two decades and is seen as a figurehead of the country's military conflicts with Iran and the United States.
Napoleon Bonaparte was a French military general who crowned himself the first emperor of France. His Napoleonic Code remains a model for governments worldwide.
Mongolian warrior and ruler Genghis Khan created the largest empire in the world, the Mongol Empire, by destroying individual tribes in Northeast Asia.
Kim Jong Il's dominating personality and complete concentration of power have come to define the country North Korea.
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Adolf Hitler was the leader of Nazi Germany. His fascist agenda led to World War II and the deaths of at least 11 million people, including some six million Jews.
Francisco Franco led a successful military rebellion to overthrow Spain's democratic republic in the Spanish Civil War, subsequently establishing an often brutal dictatorship that defined the country for decades.
Benito Mussolini created the Fascist Party in Italy in 1919, eventually making himself dictator prior to World War II. He was killed in 1945.
Rafael Trujillo was a dictator of the Dominican Republic for decades. He was assassinated in 1961.
Known for running a corrupt, undemocratic regime, Ferdinand Marcos was the president of the Philippines from 1966 to 1986 before fleeing to the United States.
Kim Il-sung served as premier and president of North Korea and ran the country for decades, spearheading the creation of an Orwellian regime.