Planning and Preparation:
Following the Tehran Conference, President Franklin Roosevelt and British Prime Minister Winston Churchill continued the preparation for an invasion of France and chose General Eisenhower as Operation Overlord's, the invasion's code name, commander. Many American soldiers, airplanes, and tons of equipment were then sent to England for the invasion. The last decision to be made regarded the date for the invasion which proved to be very difficult, as there were many stipulations to ensure this attack was successful. Firstly, the assault had to take place at night so that the ships crossing the Channel were not visible. Secondly, a low tide was necessary (at dawn) for arrival in order for the troops to see obstacles on the beach and their targets. Also, a moonlit night was crucial so the paratroopers could see where to land. Lastly and most importantly, good weather was needed for the airplanes and landing craft. With all of the aforementioned conditions, few days in each month were suitable for the attack. The first window of opportunity was from June 5 to June 7, 1944. When June 5, 1944, approached, however, the weather proved to be undesirable with many clouds, strong wind, and rough waves. The invasion was pushed back to June 6, with the weather was still not ideal but improved and navigable.