Fortified Defenses: The Normandy coast, chosen as the landing site for D-Day, had been extensively fortified by the Germans. They constructed a complex system of bunkers, beach obstacles, underwater mines, and artillery batteries to repel any potential invasion. The German fortifications made the landing beaches very difficult to navigate and highly contested zones for the attacking troops.
High Tide: The landings were planned for June 6, 1944, when the tide was at its lowest, allowing the attacking forces to clear obstacles more effectively. However, weather conditions forced a delay of several days, resulting in the landing taking place at a higher tide. This made it harder for the troops to reach the beach and rendered the obstacles more challenging to overcome.
Heavy Seas: Rough weather conditions in the English Channel hindered the landing operations considerably. The high waves made it difficult for landing craft to approach the shore and caused some to capsize. Additionally, the rough sea conditions affected air support and naval gunfire accuracy.
German Intelligence and Deception: The Germans had reasonably accurate intelligence about the impending Allied invasion and had prepared accordingly. Their forces were on high alert, and extensive deception plans, such as fake troop concentrations, were employed to mislead the Allies. The Allies were, to a certain extent, surprised by the strength of the German defenses.
German Reserves and Reinforcements: The Germans had substantial reserves positioned in the region. They were able to quickly respond and counterattack the Allied forces as they moved inland from the beaches. This made rapid progress challenging for the Allies.
Initial Disorganization and Casualties: The initial landings were chaotic, with troops facing heavy fire and obstacles. Many units suffered heavy casualties and lost cohesion, making it difficult to organize a coherent advance. This disrupted the Allies' plans and slowed their progress.
Stubborn German Resistance: The German troops defending Normandy were well-trained and highly motivated. They fought fiercely and tenaciously, despite being outnumbered. The Allies faced strong resistance at various points, requiring intense fighting to secure their positions and advance.
In summary, the D-Day attack proved more difficult than previous battles due to a combination of factors, including heavily fortified defenses, challenging weather conditions, German intelligence, rapid reinforcement, initial disorganization, and fierce resistance from the German defenders. These factors combined to make the Normandy landings one of the most challenging and critical operations of World War II.