The murder of the Russian Tsar Nicholas II and his wife, four daughters and young son in 1918, plus how the Soviet Union struggled to feed its people in the 1950s; also the IRA attacks on mounted troops in London's Hyde Park in 1982, the Zionist bombing of the British headquarters in Jerusalem in 1946 and the first steps towards a nuclear non-proliferation treaty.

(Photo: Nicholas II, Tsar and his family. From left to right - Olga, Maria,Tsar Nicholas II,Tsarina Alexandra, Anastasia, Tsarevitch Alexei and Tatiana. Credit: Press Association