On 24th December 1979 Soviet troops poured into Afghanistan in support of an anti-government coup. The Soviet occupation would last for nine years.

Plus, the hidden history of the board game Monopoly, the invention of chemotherapy, the heaviest aerial bombardment of the Vietnam war at Christmas 1972, and the street-performer origins of the global circus phenomenon Cirque du Soleil.

Picture: Russian tanks take up positions in front of the Darulaman (Abode of Peace) Palace in Kabul, January 1980. (Henri Bureau/Corbis/VCG via Getty Images)