emergency currency, notgeld, 25 pfennig, Germany

Instituted in the hope of avoiding war, appeasement was the name given to Britain’s policy in the 1930s of allowing Hitler to expand German territory unchecked. Most closely associated with British Prime Minister Neville Chamberlain, it is now widely discredited as a policy of weakness. Yet at the time, it was a popular and seemingly pragmatic policy.

Military conflict took place during every year of the 20th Century. There were only short periods of time that the world was free of war. The total number of deaths caused by war during the 20th Century has been estimated at 187 million and is probably higher.

The first pilotless vehicles were built during the First World War but drones now have many functions.