You know the old joke about the guy who did a bunch of cool stuff, then gets really angry that his nickname doesn't reflect any of that stuff, and eventually shouts "You fuck one sheep!"? September 30, 1938 was the day that British Prime Minister Neville Chamberlain fucked a sheep.
In March of that year, the Anschluss saw saw Hitler annex Austria into Germany, to which Chamberlain responded, "Heaven knows I don't want to get back to alliances but if Germany continues to behave as she has done lately she may drive us to it."
Having suffered little more than a finger wag for his efforts in Austria, Hitler then turned his greedy eyes toward the Sudetenland, the areas mainly around the exterior of what was then Czechoslovakia, but were inhabited largely by German-speaking people.
Soon sabers began rattling, a couple of shots were fired and tensions were rising. Chamberlain and his crew decided to see what Hitler had to say for himself during his speech at Nuremberg on September 12--if Hitler seemed overly bellicose (try to imagine such a thing), Chamberlain would hop on a plan bound for Germany, where he would confront the fuhrer.
Come the 12th, Hitler let it be known that he'd had enough:
"I have stated that the 'Reich' would not tolerate any further oppression of these three and a half million Germans, and I would ask the statesmen of foreign countries to be convinced that this is no mere form of words."
The following day, English intelligence got wind of the fact that the Nazis were planning to rolling into the Sudetenland on the 25th. Chamberlain was on a plane two days later. Over the course of two meetings held a week apart, the two sides hammered out the Munich Agreement, signed by the UK, Germany, France and Italy, which ceded the Sudetenland to Germany,
Upon deplaning on September 30 at the Heston Aerodrom in west London, Chamberlain addressed the crowd, famously waving in the air the useless piece of paper signed by Hitler:
The settlement of the Czechoslovakian problem, which has now been achieved is, in my view, only the prelude to a larger settlement in which all Europe may find peace. This morning I had another talk with the German Chancellor, Herr Hitler, and here is the paper which bears his name upon it as well as mine. Some of you, perhaps, have already heard what it contains but I would just like to read it to you: " ... We regard the agreement signed last night and the Anglo-German Naval Agreement as symbolic of the desire of our two peoples never to go to war with one another again".
Hitler invaded Poland less than a year later, kicking off WWII.