King Charles III gives thanks to D-Day veterans during event with Prince William, Queen Camilla

King Charles III, Queen Camilla and Prince William are commemorating the 80th anniversary of the D-Day Landings as a family.

The British monarch gave a passionate speech remembering veterans at an event in English coastal city Portsmouth on Wednesday. D-Day, formally known as Operation Overlord, refers to the joint air and sea invasion of German Nazi-occupied Normandy, France, by World War II Allies and the French Resistance in 1944.

"Today we come together to honor those nearly one hundred and sixty thousand British, Commonwealth and Allied troops," who "assembled here and along these shores to embark on the mission which would strike that blow for freedom and be recorded as the greatest amphibious operation in history," Charles said. "All knew that both victory and failure were possible, and none could know their fate."

He continued, "It is a near impossible task to imagine the emotion of that day: the pride of being part of so great an enterprise, the anxiety of in some way not coming up to scratch, and the fear of that day being their last."

Sharing a personal anecdote, the king said he recently spoke to a veteran who said they "remember with such heartbreaking clarity the sight of those many soldiers lying on the beach, who drowned before they could even engage in combat."

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"And as we remember, with humility, pride and gratitude, let us never forget that the soldiers who fought in the campaign launched from this place came from thirty nations, from across the United Kingdom, the Commonwealth and Allied countries," he continued, also honoring Europe Allied forces fighting against Nazi's in Italy and an ongoing war in Japan fought by Britain and Sikh, Muslim and Hindu soldiers from India, that occurred simultaneously with D-Day.

Charles added: "While it was the frontline troops who faced the greatest personal dangers, the privations and sacrifices of war were endured by so many more."

"So, as we give thanks for all those who gave so much to win the victory, whose fruits we still enjoy to this day, let us, once again, commit ourselves always to remember, cherish and honor those who served that day and to live up to the freedom they died for by balancing rights with civic responsibilities to our country," he concluded. "For we are all, eternally, in their debt."

William and Camilla joined Charles, who recently re-entered the spotlight after taking a step back from public duties while undergoing treatment for an undisclosed form of cancer.

Charles will continue treatment for an undetermined amount of time, but according to Buckingham Palace, "doctors are sufficiently pleased with the progress made so far that The King is now able to resume a number of public-facing duties."

The palace also noted his outings would "remain subject to doctors' advice," but he will not have a full summer programming.

King Charles, Queen Camilla and Prince William to go to France. Is Princess Kate joining?

On Thursday, Charles will have his first trip out of the country since his public return. The British monarch, Camilla and William will head to France for more commemorative events for the official D-Day.

It has not been announced whether William's wife Princess Kate will travel with the bunch after Kensington Palace announced in March that she diagnosed with cancer and underwent "a course of preventive chemotherapy treatment."

"I wanted to take the opportunity to thank you personally for all the wonderful messages of support and for your understanding whilst I've been recovering from surgery," Kate said in a video released by the palace at the time. "It has been an incredibly tough couple of months for our entire family."

"In January, I underwent major abdominal surgery in London. And at the time, it was thought that my condition was non-cancerous," she continued. "The surgery was successful. However, tests after the operation found cancer had been present."

At the time of her surgery, Kensington Palace predicted she'd return to public duties at the earliest after Easter.

Contributing: Jay Stahl