Ken Peppercorn almost didn’t make it to Gold beach. He fell off the ramp of his landing craft into an underwater shell hole. “I nearly went under. I was loaded up with all the equipment – hand grenades in my pockets, magazines in my pouches, and everything else I could carry.”

The sea around him was red with blood. “It was quite a mess, but you just had to keep going.” He managed to surface and get to the beach. “We were under fire but I scrambled up the dunes and found a shell crater to shelter in. I was so hungry that the first thing I did was get my rations out and make porridge,” he said.

It was a few days after D-day, and Peppercorn was 22 years old. Within a week of landing in Normandy, he had been badly wounded in the leg by shrapnel and taken prisoner by the Germans. Nearly all the troops in his company were dead, among 12,000 young men killed and injured in an operation to capture the town of Caen. “I just kept saying to myself, ‘you’re going to get back home’.”

Now 97, Peppercorn will on Sunday board a ship chartered by the Royal British Legion that will take 300 D-day veterans to commemorative events on the south coast of England before crossing the Channel to Normandy for the 75th anniversary on 6 June. The Queen, Prince Charles, Theresa May, Donald Trump, French president Emmanuel Macron, and German chancellor Angela Merkel will be among world leaders and dignitaries taking part in five days of events.

Hundreds of parachutists will recreate the historic airdrop made from more than 800 Douglas C-47 Skytrains (Dakotas) over Normandy. The British dead will be remembered at a commemoration at the Commonwealth War Graves Commission cemetery in Bayeux, and Trump will be present at a ceremony at the Normandy American Cemetery in Colleville-sur-Mer.

D-Day veteran Ken Peppercorn celebrating his 97th birthday in early May. Photograph: Courtesy of the Peppercorn family

A dwindling number of D-day veterans – now all aged over 90 – will take part in services on both sides of the Channel. It is likely to be the last big commemorative occasion involving those who took part in the largest amphibious assault in history.

Operation Overlord – the codename given to the land, naval and air operations – began just after midnight on 6 June 1944 with the first of 24,000 airborne troops being dropped on to French soil. Soon after sunrise, Allied naval and air forces began bombing German defences, and the seaborne invasion got under way.

Ken Peppercorn in his wartime uniform. Photograph: Courtesy of the Peppercorn family

Thousands of vessels carrying almost 160,000 troops crossed the Channel, heading towards a 50-mile stretch of the Normandy coast. Under heavy gunfire, the first men scrambled on to mined beaches strewn with barbed wire. Veterans have described scenes of pandemonium, with deafening noise and the agonised screams of dying and injured men – many of whom had enlisted only weeks before.

Those landing in subsequent waves had to wade through bodies to reach the shore.

“You were just trying to stay alive,” recalled one. “It was total chaos, total noise.” By the end of the day, there were more than 10,000 Allied casualties – mainly Britons, Americans and Canadians. At least 2,500 had been killed: the US D-Day Memorial Foundation puts the death toll at 4,413. The Germans also suffered heavy casualties.

The operation – which had been planned for more than a year and was delayed by 24 hours because of poor weather – lasted almost three months. By its end, a second front in the liberation of Europe from Nazi occupation had been established, paving the way for victory in 1945.

Leslie Withers, now a great-grandfather, landed on Juno beach on 6 June 1944. Photograph: Courtesy of the Withers family.

Lance Corporal Leslie Withers with the 86th Heavy Anti-Aircraft Regiment Workshop, REME, in 1943. Photograph: Courtesy of the Withers family.

Leslie Withers, now 94, landed at Juno beach after crossing the Channel on an American cargo ship that sailed from the London docks. “We had no idea why we were getting on this ship until the officer got us together to tell us we were part of the invasion force to free Europe. We were quite apprehensive. As we were going down the Thames, people started coming out to wish us well. When we passed the Ford factory in Dagenham, thousands of women were waving, and some were crying. That was food for thought for us.

The vessel carrying Withers, who had joined the army at 14 six years earlier, was “among a huge flotilla of ships, as far as the eye could see. The organisation [of the operation] was terrific”. By the time his ship reached Juno, German forces had been largely driven back by the first wave of assault forces. “The most frightening thing was getting off the cargo ship on to the landing craft. We had to climb down netting with packs on our backs and carrying our rifles, and jump at the right time so as not to fall between them [the ships].

“There was an officer with a huge walrus moustache shouting at us to get off the beach as fast as possible because of the German snipers. We marched about a mile inland, and dug ourselves in behind a farm. We lived in those holes for a couple of weeks.”

On Wednesday, Withers will attend the national commemorative event in Portsmouth in the presence of the Queen and Trump. “It’s quite an honour that all this is being put on for us, though I don’t suppose there’s all that many of us left now,” he said.

Peppercorn is hoping to meet “some chaps” on the British Legion boat that he befriended at previous anniversary events. “I feel a little bit emotional. I used to have nightmares for ages – you don’t ever forget. But I was one of the fortunate ones.”