•  A pogrom (from Russian: meaning "wreaking of havoc") is a massive violent attack on a particular group; ethnic, religious or other, with simultaneous destruction of their environment (homes, businesses, religious centers). The term has historically been used to denote massive acts of violence, either spontaneous or premeditated, against Jews, but has been applied to similar incidents against other, mostly minority, groups.

•  His Imperial and Royal Highness Archduke Franz Ferdinand Karl Ludwig Joseph of Austria-Este (sometimes called Francis Ferdinand in English) (December 18, 1863 – June 28, 1914) was born in Graz, Austria and was a Habsburg Archduke of Austria and heir to the Austro-Hungarian throne. His assassination by Gavrilo Princip on June 28 , 1914 in Sarajevo, Austrian-annexed Bosnia-Herzegovina, precipitated the Austrian declaration of war against Serbia which triggered World War I .

•  The Berlin Airlift , one of the major crises of the Cold War, occurred from June 24, 1948 - May 11, 1949 when the Soviet Union blocked Western rail and road access to West Berlin. In June 1948, the Soviet Union attempted to control all of Berlin by cutting surface traffic to and from the city of West Berlin. Starving out the population and cutting off their business was their method of gaining control. The Truman administration reacted with a continual daily airlift which brought much needed food and supplies into the city of West Berlin. This Airbridge to Berlin lasted until the end of September of 1949---although on May 12, 1949, the Soviet government yielded and lifted the blockade. The crisis abated after the Soviet Union did not act to stop American, British and French airlifts of food and other provisions to the Western-held sectors of Berlin following the Soviet blockade.

•  A Bolshevik (derived from a Russian word loosely translated as "majority") was a member of a faction of Bolsheviks of the Russian Social Democratic Labor Party (RSDLP), a Marxist political party. Bolsheviks led by Vladimir Lenin seized power in Russia in 1917, a world-historical event known as the October Revolution.The other faction of the RSDLP was known as the Mensheviks, derived from "minority".

•  Arthur Neville Chamberlain (18 March 1869 – 9 November 1940) was a British politician and Prime Minister of the United Kingdom from 1937–1940. Chamberlain is perhaps the most ill-regarded British Prime Minister of the 20th century, largely due to his policy of appeasement towards Nazi Germany regarding the abandonment of Czechoslovakia to Hitler at Munich in 1938.

•  The Crimean War lasted from 28 March 1854 until 1856. It was fought between Russia and an alliance of the United Kingdom, France, and the Ottoman Empire, joined somewhat tardily by Piedmont-Sardinia.The majority of the conflict took place on the Crimean peninsula in the Black Sea.

•  The Dachau concentration camp was a Nazi German concentration camp near the city of Dachau, north of Munich, in southern Germany.The camp was constructed in a disused gunpowder factory and was completed on March 21, 1933. Together with the much larger Auschwitz extermination camp, Dachau has come to exemplify Nazi concentration camps to most non-experts.

•  The Battle of Dunkirk was a major battle during World War II which lasted from around May 26 to June 4, 1940. A large force of British and French were cut off in north-east France by a German armoured advance to the Channel coast at Calais. More than 300,000 troops were evacuated from Dunkirk and the surrounding beaches in May and June 1940. At the time the British Prime Minister Winston Churchill said it was "a miracle of deliverance".

•  The "Dreyfus Affair" was a political scandal which divided France for many years during the late 19th century.It centered on the 1894 treason conviction of Alfred Dreyfus , a Jewish artillery officer in the French army. Dreyfus was charged with passing military secrets to the German Embassy in Paris. Dreyfus was, in fact, innocent; the conviction rested on false documents, and when high-ranking officers realised this they attempted to cover up the mistakes. The writer Émile Zola exposed the affair to the general public in the literary newspaper L'Aurore (The Dawn) in a famous open letter to the Président de la République Félix Faure, titled J'accuse! (I Accuse!) on January 13, 1898. In the words of historian Barbara W. Tuchman, it was "one of the great commotions of history".

•  Fifth column refers to any clandestine group of people which works covertly inside a nation to undermine its strength (psychological warfare) while the nation is simultaneously suffering an overt attack by a foreign power or another faction in a civil war.The term was coined by General Emilio Mola in a radio address during the Spanish Civil War (1936–1939). As a Nationalist general, he sent four army columns to capture Madrid, which was being defended at that time by the Republican forces. The general referred to his hidden supporters inside the capital as his fifth column . The term caught on after the address was widely reported by international media.