Meanwhile, the service in Staffordshire featured the reading of a specially- commissioned poem by the arboretum's poet in residence, Arji Manuelpillai.
"A Sonnet For Us All captures the stories etched into the hundreds of memorials within the National Memorial Arboretum, it invites people to listen, reflect and consider the emotion that was the inspiration for these sculptures," Mr Manuelpillai said.
"These human connections, and the gentle responsibility to carry love forward, are themes that resonate not only with me, but also with HRH The Princess of Wales, for whom the importance of service and compassion lies especially close to the heart."
Queen Camilla joined commuters on the 09:28 train from Chippenham in Wiltshire to Paddington where a service was held for service personnel and their families.
Later on Tuesday, William will join the King and Queen at Windsor Castle where a reception will honour veterans who served in the Pacific during the Second World War.
The event, which the Duke of Edinburgh and the Duchess of Gloucester will also attend, continues the commemorations for the 80th anniversary of VJ Day - or Victory over Japan Day.
Elsewhere around the world French President Emmanuel Macron attended a wreath-laying ceremony in the Champs-Elysees in Paris to mark the signing of the armistice at the 11th hour of the 11th day of the 11th month.
Meanwhile the Princess Royal is in Australia, visiting Brisbane's Galipolli Barracks where she laid a wreath.
Along with her husband, Sir Timothy Laurence, Princess Anne also met current and former armed forces and their families.