Short answers, pulled from the story.
Germany decided to seize Czechoslovakia on the 5th of November 1937 to secure essential raw materials like iron, oil, chrome, and nickel for its armament program. The Four-Year Plan had strained foreign exchange reserves, making it necessary to import these resources from abroad.
The Munich Agreement was signed by Germany, Italy, France, and Britain on the 29th of September 1938 to allow the takeover of the Sudetenland. The Czechoslovak government capitulated on the 30th of September despite opposition from its army.
German troops entered the remaining Czech parts of Czechoslovakia on the 15th of March 1939 and occupied the country until the Wehrmacht surrendered on the 8th of May 1945. Soviet troops arrived on the 9th of May 1945 to officially end the occupation following the Prague uprising.
Jozef Gabčík and Jan Kubiš carried out Operation Anthropoid on the 27th of May 1942 to assassinate Reinhard Heydrich who served as Reichsprotektor of Bohemia and Moravia. This event triggered brutal retaliation campaigns including the destruction of Lidice and Ležáky.
The Beneš decrees laid the ground for the deportation of approximately 3 million Germans and Hungarians from their homeland between 1945 and 1946. An estimated 1.6 million ethnic Germans were deported to West Germany while another 800,000 went to East Germany.