King Charles III is to take part in his first Remembrance Sunday event as king, laying a wreath in tribute to the United Kingdom and Commonwealth war dead, as Britain's new Prime Minister also lauds Ukraine's defenders.
The 73-year-old monarch had previously deputised for his mother Queen Elizabeth II, who died in September aged 96 after a year of failing health.
Since 2017, she had watched the annual service from a balcony of the Foreign, Commonwealth and Development Office overlooking the Cenotaph.
Last year, a back complaint forced her to miss the ceremony in central London, just weeks after an unscheduled overnight stay in hospital.
Charles, who served in the Royal Navy in the 1970s, laid a wreath on her behalf.
Now king and Commander-In-Chief of British forces, he will lay his first wreath at the war memorial as reigning monarch.
The ring of red artificial poppies - Britain's symbol of remembrance - is mounted on black leaves, with a ribbon in the king's scarlet, purple and gold horseracing colours.
Buckingham Palace said a similar wreath would be laid on behalf of his wife, Queen Consort Camilla, for the first time.
Camilla, 75, will watch the event from the FCDO balcony.
Two minutes' silence marks the start of the sombre tribute. It begins on the stroke of 1100 GMT with the distinctive chime of Big Ben, which returns to regular service after a five-year renovation.
New Conservative leader Rishi Sunak will attend his first Remembrance Sunday as PM.
"This year more than ever, we are reminded of the huge debt of gratitude we owe those who lay down their lives to protect their country," Sunak said in a statement.
"As we fall silent together on Remembrance Sunday, we will honour the memories of the men and women we have lost, and pay tribute to the brave soldiers of Ukraine as they continue their fight for freedom."
Remembrance Sunday is the culmination of days of events to pay tribute to all those who lost their lives in conflict.
On Thursday, Camilla laid a cross at the Field of Remembrance outside London's Westminster Abbey, alongside 70,000 other symbols left by military associations, and a space dedicated to the late queen.
On Friday, Armistice Day, marking the end of hostilities in World War I, a service was held at the National Memorial Arboretum in central England.
The king, queen and senior family members on Saturday attended an annual concert organised by the Royal British Legion veterans' charity.
On Sunday, around 10,000 veterans will march past the Cenotaph including 400 who fought in the Falklands War, 40 years ago.
Other royals expected on Sunday include Charles's eldest son and heir, Prince William, and William's wife Kate.