Prince William, Duchess Kate mark 75th anniversary of Auschwitz liberation

On Monday, the Duke and Duchess of Cambridge marked International Holocaust Remembrance Day by attending a ceremony held at Central Hall in Westminster, London.

The service, which was joined by a number of high-profile religious and civic leaders from the United Kingdom, honored the victims and heroes of the Holocaust, as well as those killed in the genocides in Cambodia, Rwanda, Bosnia and Darfur.

Jan. 27 also marked the 75th anniversary of the liberation of Auschwitz-Birkenau, the largest and perhaps the most well-known of the Nazi concentration and death camps.

Monday's ceremony was held by Holocaust Memorial Day Trust, of which Prince William is a patron. The 37-year-old gave a speech at the service, reading a letter from a friend of his great-grandmother, Princess Alice of Battenberg. The princess, Prince Philip's mother, was well known for her work hiding Jews in her home during the Nazi occupation of Greece.

The letter read:

"My family would not exist without the courageous act of Princess Alice. Her story of incredible courage must keep being told in her memory. My generation, the past generation and the future generation are, and will eternally be, grateful to Princess Alice for the great act of bravery, risking her own life to take in a family in need.”

Kate and William's outing comes just a day after the palace released touching photographs taken by the Duchess of Cambridge of Holocaust survivors and their grandchildren. The royal's photos, taken at Kensington Palace, will join a Holocaust exhibition later this year.

"It was a true honour to have been asked to participate in this project and I hope in some way Yvonne and Steven’s memories will be kept alive as they pass the baton to the next generation," Kate said.

The first photo taken by the royal is of Steven Frank alongside his grandaughters Maggie and Trixie. Frank was one of 93 children who survived the Theresienstadt Ghetto, where over 15,000 children were sent.

The second snapshot shows Yvonne Bernstein, who survived in hiding in France, with her granddaughter Chloe.

The ceremony on Monday was just one of the many held worldwide to mark the tragedy. On Monday, the Earl of Wessex met the son of Sir Nicholas Winton, a British man who saved 669 Czech children from the Nazis. Winton was knighted by Queen Elizabeth in 2003, and he passed away in 2015 at 106.

On Monday, the Duchess of Cornwall also traveled to Poland to mark the liberation of Auschwitz at the camp itself.

Last week, the Prince of Wales traveled to Jerusalem to attend the World Holocaust Forum, where he called on world leaders to make Holocaust education a priority to ensure the memories of those who bore witnesses live on.

"Almost a lifetime has passed since the horror of the Holocaust unfolded on the European continent and those who bore witness to it are sadly ever fewer," he said. "We must commit ourselves to ensuring that their stories live on to be known and understood by each successive generation."

"The Holocaust must never be allowed to become simply a fact of history," he continued. "We must never cease to be appalled nor moved by the testimony of those who lived through it."