Hitler came to power in Germany in 1933. He was appointed Chancellor of Germany by the President of the Weimar Republic. Once in power as Chancellor, Hitler and the Nazis worked to consolidate power and quickly quashed opposition. In 1934 they held a referendum in which Hitler was elected as dictator of the nation. The election was highly controversial and contentions as the Nazi Party worked to manipulate public opinion and suppress opposition.

The reform policies of glasnost and perestroika were initiated by Mikhail Gorbachev in the Soviet Union in the 1980s. The primary purpose of glasnost, which means "openness" was to improve the transparency of the Soviet political system and allow more people to be included in the political process.

The Qing Dynasty was the last dynasty of imperial Chinese history. In the early twentieth century civil disorder was breaking out all over China and the dynasty was replaced by the Republic of China (first in 1912, and then again in 1917) led by revolutionary leader Sun Yat-Sen. 

The Cultural Revolution in China was a time of widespread state-organized persecution and suppression of opposition. It might reasonably be compared to the Great Purge in the Soviet Union. The Great Purge took place from 1936 to 1938 and involved the suppression of peasants, the wholesale execution and restructuring of army leadership, and the forced imprisonment and torture of hundreds of thousands of people.

Reza Shah led a coup against a British-dominated government in Iran and declared himself Shah (King) of Iran. He ruled for almost two decades, until deposed by the Anglo-Soviet invasion of Iran in 1941. The dynasty he founded lasted until the Iranian Revolution of 1979. Reza Shah is a controversial figure, particularly in western history, but his reign was marked by a series of modernizing reforms in Iranian society.

The Cultural Revolution was implemented by Mao Zedong in 1966. Its stated goal was to eliminate the influence of capitalism and traditional Chinese culture from modern Chinese society. In practice it involved the suppression of intellectuals and dissidents, the destruction of historical sites, the forced imprisonment, torture, and humiliation of opposition, and widespread communal disharmony throughout Chinese society.

Bloody Sunday took place in Russia in 1905, during the first Russian Revolution. It involved the massacre of peaceful demonstrators in St. Petersburg by forces associated with the Russian Tsar Nicholas II. It contributed to the decline of the ruling Romanov dynasty.

The Solidarity Movement in Poland was led by Lech Walesa. The Solidarity Movement was a widespread labor movement that took place in Soviet-controlled Poland in the 1980s. It was a large factor in Poland’s struggle for independence and somewhat influential in the downfall of the Soviet Union.

The Soviet Invasion of Afghanistan began in 1979 and lasted until 1989. It began when Soviet forces, at the request of the Afghan government, sent troops into Afghanistan to suppress disorder. Those troops ended up staging a coup in Kabul and installing a rival communist leader. The invasion led to the forced migration of millions of Afghans and contributed to the decline of the Soviet Union. It also paved the way for the rise of Taliban in Afghanistan as they came to fill the power vacuum left following the withdrawal of Soviet forces.

Glasnost and perestroika were two reform policies adopted in the waning years of the Soviet Union, during the rule of Mikhail Gorbachev. Perestroika means restructuring, and refers to the restructuring of the Soviet political and economic system in an attempt to make communism more viable. Glasnost means openness, and refers to Gorbachev’s efforts to improve the transparency and inclusiveness of the Soviet political process.