King Charles will meet lawmakers in parliament in London on Monday before flying to Edinburgh to join his siblings in a solemn procession when the coffin of his mother Queen Elizabeth is taken to the city's historic cathedral.
The new monarch will also join senior royals for a vigil at St. Giles' Cathedral where the coffin will lie at rest before being flown to London on Tuesday.
Since Elizabeth's death aged 96 at Balmoral Castle, her Scottish holiday home, a choreographed series of plans to mourn Britain's monarch of 70 years has been put into operation.
On Sunday, her oak coffin, draped in the Royal Standard of Scotland with a wreath on top, was taken by hearse on a six-hour journey from Balmoral through picturesque Scottish countryside, villages, small towns and cities to Edinburgh.
Tens of thousands of well-wishers lined the roads to pay their respects, while huge crowds, some in tears, gathered in Edinburgh to greet the cortege.
"I think when the queen's coffin emerged from Balmoral Castle yesterday, I think that it was a moment of enormous significance," John Swinney, Scotland's Deputy First Minister told BBC radio.
"And I think people drew breath, because what we've all been living through over the last few days suddenly became real, it became visible."
Before setting off for Scotland, Charles, 73, who automatically became king of the United Kingdom and 14 other realms including Australia, Canada, Jamaica, New Zealand and Papua New Guinea, will travel to the British parliament for another traditional ceremony.
At Westminster Hall, lawmakers from both the House of Commons and the upper House of Lords will express their condolences for the death of his mother, and the king will deliver a response.
He will then fly to Edinburgh with his wife Camilla, the Queen Consort, to join his sister Anne and brothers Andrew and Edward.
The queen's children will walk behind the hearse as the coffin of their mother is taken to St. Giles' Cathedral, flanked by soldiers.
Crown of Scotland
When it arrives at the church, the Duke of Hamilton and Brandon, the premier Scottish peer, will place the Crown of Scotland on the coffin.
After a service, the coffin will rest at the cathedral for 24 hours to allow people to pay their respects. A continuous vigil will be mounted by soldiers from the Royal Company of Archers - the sovereign's 'Body Guard in Scotland'.
Charles, who will also visit the Scottish parliament and meet Scotland's First Minister Nicola Sturgeon, will later mount a vigil at 7:20 p.m. along with other royals.
On Tuesday, the coffin will be flown to London where on Wednesday it will begin a period of lying in state until early on Sept. 19 - the day of Elizabeth's state funeral - on a catafalque at Westminster Hall.
It will be guarded by soldiers or by Yeoman Warders - known as beefeaters - from the Tower Of London.
Members of the public will be allowed to process past the coffin, which will be covered by the Royal Standard with the sovereign's Orb and Sceptre placed on top, for 24 hours a day until 6:30 a.m. on Sept. 19.
"Those wishing to attend will be required to queue for many hours, possibly overnight," the government said in a statement. "Large crowds are expected and people are encouraged to check ahead, plan accordingly and be prepared for long wait times."
Meanwhile thousands of people are continuing to gather at royal palaces across Britain, bringing flowers. In Green Park near London's Buckingham Palace, where some of the tributes are being taken, long lines of bouquets now snake around the park allowing mourners to read the tributes.
Other well-wishers have attached their messages of condolence to trees.
"It's really touched me, losing the queen," Amy Gibbs, 43, said outside Buckingham Palace. "I think she was an amazing lady that did her absolute best and gave us everything."
Britain last saw such a display of public mourning in 1997 following the death of Charles's first wife, Princess Diana, in a car crash in Paris.
"It reminds me of Diana 25 years ago," Helen Soo, 59, said. "I was much younger in those days, I slept overnight in Hyde Park and this is multiplied by 100 probably."