On the morning of June 6, 1944, a significant date that would go down in history, the sky dawned grey with heavy clouds and a four-foot sea.

This was to be the Allies' Longest Day.

During the weeks preceding the significant date, the Southern Coast was transformed into an expansive military hub. Roads and quiet lanes buzzed with a variety of army vehicles, while residents became accustomed to the sight of American and British troops camping close to their homes.

At the bustling harbours of Southampton and Portsmouth, a multitude of landing craft, supply vessels, and warships lined up from bow to stern, creating a formidable sight. Meanwhile, on the distant horizon, additional ships were gradually converging from various ports in the United States and across the British coastlines.

Preparing for the imminent mission, aircraft and gliders were being readied at airfields throughout the Southern region. Paratroopers diligently rehearsed their pivotal responsibilities, receiving extensive training sessions, while ground troops and naval forces honed their skills in anticipation of spearheading the forthcoming landings.

As the situation grew more urgent, makeshift barracks and rows of tents appeared in every available space. The landscape transformed as individuals clad in khaki uniforms populated the area. Approaching the pivotal day, sections were gradually cordoned off and security measures heightened. All leave was cancelled.

Launching what would later be dubbed "the great crusade," Operation Overlord saw the coordination of 7,000 ships, 11,000 aircraft, and 3 million troops, a massive mobilization effort led by General Eisenhower.

Daily Echo: Troops make their way up the Normandy beaches whil efacing heavy fire from German encampments

In the midst of meticulous preparations and concealed strategies, a sudden twist of fate almost derailed the carefully orchestrated invasion plan. The relentless onslaught of a powerful north-westerly gale posed a significant threat to the success of the operation.

In the command centre located at Southwick House, near Fareham, Eisenhower determined a 24-hour postponement of the landings. The immense strength of the Allied forces awaited the opportune moment when a temporary break in the weather appeared, prompting Eisenhower to initiate the largest coordinated land, sea, and air operation in history.

Just after midnight on June 6, a relentless sea bombardment ignited the early hours with a series of bombing raids targeting German fortifications lining the shores of France.

During the dark of night, airborne soldiers descended from the sky using gliders or parachutes, stealthily infiltrating enemy territory to capture key positions.

As the turbulent waters of the Channel churned relentlessly, a wave of nausea swept through the numerous soldiers bracing themselves for the imminent peril of their daring assault on the beaches.

Under the dawn light, the troops launched a fierce and relentless assault as they made their way onto the shore. Despite the increasing number of casualties, the intense battle persisted.

Slowly but surely, the British advanced, steadily securing each objective they aimed for. Meanwhile, to the west, the Americans faced formidable resistance.

Daily Echo: Pic caption A: On the March: American GIs marching through Southampton in the lead up to the

Before the invasion began, the pre-invasion bombing failed to eliminate the German forces.

Further west beneath the rugged cliffs of Pointe du Hoc, Colonel James E Rudder and his squadron of American rangers, equipped with grappling hooks and London Fire Brigade ladders, braced themselves to conquer the daunting vertical rock surface amidst a relentless onslaught of machine gun bullets and hand grenade explosions.

As their comrades plummeted to their death below, the brave rangers continued their advance without hesitation. They eventually found themselves engaged in close combat with German forces within a labyrinth of subterranean tunnels atop the cliff.

And still the invasion force kept pushing forward.

Throughout the day, a steady stream of troops flooded ashore, moving deeper into the territory while Allied aircraft circled above, scanning and attacking enemy positions.

By the evening Winston Churchill was able to tell the House of Commons that Operation Overlord "is proceeding in a thoroughly satisfactory manner. Many dangers which appeared extremely formidable are now behind us."