Kaiser Wilhelm II of Germany, Czar Nicholas II of Russia, and King George V of Britain were all cousins and grandsons of Queen Victoria. Their relationships were strained to say the very least. \

After the initial wave of independence for African countries from Europe, Eritrea remained a part of Ethiopia. Armed groups in the Eritrean region fought a protracted secessionist war until gaining independent sovereignty after a UN supported referendum in 1993. 

The Qajar Dynasty ruled Persia (which would become Iran) from 1785 to 1925.

The German and British navies met in the only full-scale clash of steel battleships in the war off the coast of Denmark in the summer of 1916. Over 250 combat ships fought over 2 days in this inconclusive battle. England lost 3 battleships and Germany lost 1. This was only the third time two steel battleships had fought, the first two during the Russo-Japanese War.

On July 1st 1916 57,470 soldiers of the British were wounded or killed in the first day of the Battle of the Somme in France. This four month long British and French fronted offensive against the German armies on the Western Front caused over 1 million causalities and did little to further the stalemate of trench warfare. Only 6 miles of ground had been taken before the armies set up for winter.

When the Provisional Government came to power in Russia, following the February/March Revolution, it kept Russia involved in the First World War. Lenin and the Bolsheviks used this to their advantage, promising to withdraw Russia from the war when they came to power. Lenin took control following the October/November Revolution and subsequently kept his promise by ending Russian involvement in World War I.

The Nuclear Non-Proliferation Treaty was signed in 1968 with the stated goal of preventing the spread of nuclear weapons to new countries. Since its inception a few states have confirmed their construction of nuclear weapons - India, Pakistan, and North Korea. Israel almost certainly has also created nuclear weapons, but has never officially confirmed this.

The Iran-Iraq War began in 1980, in the wake of the 1979 Iranian Revolution, which ushered Ayatollah Khomeini into power. It began when the forces of Saddam Hussein invaded Iran for fear that the Iranian Revolution would inspire resistance among the Shia majority population living in Sunni-controlled Iraq.

Italy invaded Ethiopia in 1935 and the military occupation of Ethiopia began in 1936. It may be understood in relation to two important topics. Firstly, it represented the culmination of Mussolini’s promise upon coming to power in Italy - that he would achieve conquest of foreign territory and the establishment of Italian colonies. Secondly, it represented the ineffectiveness of the League of Nations at preventing conflict between its member nations.

The Chinese Civil War was fought from the late 1920s until 1950. It was fought between the communist forces of Mao Zedong and the nationalist forces of Chiang Kai-Shek. It ended with the communists in control of mainland China and the nationalist forces forced to flee and establish a government in Taiwan. This situation, of a divided China, persists to this day.