On this day, the British Royal Air Force begins a bombing campaign on the German capital that coincides with the 10th anniversary of Hitler's accession to power.
The Casablanca Conference, held from January 14 to 23, saw Prime Minister Winston Churchill, President Franklin D. Roosevelt, and the Combined Chiefs of Staff meet in Morocco to discuss future war strategy following on the success of the North African invasion, which heralded the defeat of Vichy forces. One of the resolutions of the conference was to launch a combined and sustained strategic bombing effort against the Germans. Strategic bombing was the policy of using bombers to destroy an enemy's warmaking capacity, also referred to as "area bombing." Churchill described it as an "absolutely devastating, exterminating attack by very heavy bombers...upon the Nazi homeland."
To celebrate the anniversary of Hitler's 1933 appointment to the office of chancellor by then-President Paul von Hindenburg, both propaganda minister Joseph Goebbels and head of the Luftwaffe Hermann Goering planned to give radio addresses to the German masses. Goebbels intended to bolster morale by hailing an impending victory in Russia: "A thousand years hence, every German will speak with awe of Stalingrad and remember that it was there that Germany put the seal on her victory." As the speeches were broadcast, RAF fighters rained bombs on Berlin, the beginning of devastating attacks on German cities that would last until the very end of the war. To make matters even worse for the Germans, the next day a massive surrender of German troops occurred at Stalingrad.
Taken from: http://www.history.com/this-day-in-history/raf-launches-massive-daytime-raid-on-berlin [30.01.2015]