In his Commonwealth Day message, King Charles III will praise the importance of traditional alliances and international friendships in a time of "increasing pressures of conflict."
The annual celebration of the Commonwealth, which will be celebrated with a service at Westminster Abbey on Monday, will be the largest gathering of senior royals since the arrest of his brother, Andrew Mountbatten-Windsor.
Performers such as former Spice Girl Geri Halliwell-Horner and Strictly Come Dancing's Oti Mabuse will also participate.
Against the backdrop of wars in the Middle East and Ukraine, the King will praise the unifying power of the Commonwealth, a voluntary association of 56 countries.
The King's message will state, "It is often in such difficult times that the enduring spirit of the Commonwealth is most clearly visible."
The King, who has campaigned for environmental protection for many years, will also address the pressures of "climate change and accelerating change" in his written message.
He will say that the Commonwealth is "a force for good – rooted in community, committed to the kind of restorative sustainability that delivers returns on investment, rich in culture, steadfast in caring for our planet, and united in friendship and service to our people."
The mention of the importance of climate change contrasts with the approach of President Donald Trump's administration in the US, which last month reversed a decision supporting federal efforts to curb greenhouse gases.
There are reports that the King may make a state visit to the US next month, but nothing has been confirmed yet.
The annual Commonwealth Service at Westminster Abbey is usually attended by senior royals, political and religious leaders, and representatives of Commonwealth countries.
This multi-faith service, held since 1972, is a mix of music, prayer, dance, and readings that showcases the diversity of the Commonwealth. But unlike in recent years."
Software Services
Dancers from the Royal Ballet School, singers Indigo Marshall and Tarju Le'Sano will also participate, and there will be new music by composer Rekesh Chauhan.
Future issues facing Commonwealth leaders will include whether Mountbatten-Windsor should retain his place in the line of succession, following his arrest last month on suspicion of misconduct in public office and the revelations from the Epstein files.
Canadian Prime Minister Mark Carney added his voice to calls for his removal from the line of succession, following similar demands from Australia and New Zealand.
Andrew remains eighth in line to the throne, and his removal would require legislation in the UK and the approval of the 14 Commonwealth realms, whose head of state is King Charles.
Mountbatten-Windsor has denied any wrongdoing in her association with Jeffrey Epstein.
Thank you for reading this content.