The Duke of Edinburgh's funeral will be a "profound" chance for the Queen to say farewell to her husband of 73 years, the Archbishop of Canterbury has said.
"She will behave with the extraordinary dignity, extraordinary courage that she always does," Justin Welby said.
Prince Philip's funeral will take place at St George's Chapel in Windsor Castle at 15:00 BST on Saturday.
The duke's children will walk behind his hearse during the procession.
At the ceremony, there will only be 30 mourners in line with coronavirus restrictions.
Buckingham Palace said the Queen had faced "some very difficult" decisions in selecting the mourners from the 800-strong congregation originally planned, and she wanted all branches of her husband's family to be represented.
Speaking to the BBC, Mr Welby said many people had seen family members die in the Covid pandemic this year and the funeral service would "resonate very deeply for a lot of people".
He said: "I think there will be tears in many homes because other names will be on their minds, faces they've lost that they don't see again, funerals they couldn't go to as many haven't been able to go to this one because it is limited to 30 in the congregation. That will break many a heart."
Mr Welby said he expected the Queen at the service to "behave with the extraordinary dignity, extraordinary courage that she always does".
He added: "And at the same time she is saying farewell to someone to whom she was married for 73 years. I think that must be a very, very profound thing... in anybody's life."
The archbishop, who will pronounce the blessing at the funeral service, suggested that people of faith could pray for the Queen, or alternatively "sympathise and in their hearts offer their condolences to her and the hope for her to find strength in what must be an anguished moment".
Meanwhile, the Earl and Countess of Wessex and their daughter Lady Louise Windsor have been viewing flowers and cards left in memory of Prince Philip at Windsor Castle.
Earlier, the head of the UK's armed forces said the funeral will have the duke's "fingerprints [all] over it" and it "reflects his wide interests and his attention to detail".
"It's obviously been slightly affected by Covid, but nonetheless it will reflect military precision," said Gen Sir Nick Carter, chief of defence staff.
Among the funeral details that Prince Philip was involved in is the specially-modified Land Rover hearse, which the duke helped to design over 16 years. He requested it be repainted in military green and helped to design the open top rear of the car.
The duke also personally selected the regalia - medals, decorations and insignia - that will be on the altar for his funeral.
Sir Nick hailed the "extraordinary war record" of Prince Philip - who served in the Royal Navy in World War Two - and the dozens of different military decorations and awards he had.
"I think people will realise that this is a life worth looking into and I think they will be surprised by what he achieved and what he did in his 99 years," he said.
The Queen has decided that there will be no military uniforms worn by members of the Royal Family, and those attending will instead wear morning coats with medals, or day dress.
At the scene
Helena Wilkinson, news correspondent in Windsor
Behind the walls of Windsor Castle, in the spring sunshine, the Duke's youngest son and daughter-in law viewed some of the flowers left by members of the public.
Accompanied by their daughter Lady Louise, the Countess of Wessex crouched at times to read some of the many messages and tributes from organisations affiliated with Prince Philip.
One of the wreaths had been sent by the prime minister with a message paying tribute to a man whom the "nation owes more than words can say".
The hundreds of bouquets had been moved from one of the castle gates to outside St George's Chapel, where the Duke of Edinburgh's funeral will take place on Saturday.
Gardeners have been busy mowing lawns, making sure everything is just right.
A full rehearsal has also taken place. Every last detail is being pored over and practised to perfection, just as the duke would have expected, just as he would have wanted.
Windsor is a town used to big royal occasions. But many here have accepted that the day will be rather different than normal.
Streets won't be lined with mourners, a public procession won't take place.
This town though will, in its own private way, say goodbye to Prince Philip, who many here saw not just as the duke, but as a neighbour who was very much part of the community.
Prince Philip died at Windsor Castle on Friday 9 April aged 99.
The procession to the funeral service will be headed by the Band of the Grenadier Guards, followed by the Household Division and military service chiefs.
The duke's four children - the Prince of Wales, the Princess Royal, the Duke of York and the Earl of Wessex - as well as his grandsons the Duke of Cambridge, Duke of Sussex and Peter Phillips will be among those walking behind the coffin.
The Queen will travel with a lady-in-waiting in the state Bentley at the end of the procession, and enter the chapel by a side door.
In line with Covid lockdown rules, the 30-person congregation inside the chapel will put on masks and socially distance, with the Queen seated alone.
Royal historian Professor Kate Williams said she thought it would be "a very striking image" to see the Queen sitting alone rather than with the other mourners.
"They'll be wearing masks and sitting in their bubbles in St George's Chapel. And the Queen doesn't have a bubble, the bubble was Prince Philip," she told BBC Breakfast.
The other mourners include the Duchess of Cornwall and the Duchess of Cambridge as well as all of the duke's grandchildren and their spouses, apart from the Duchess of Sussex, who is heavily pregnant and will remain in the US.
The children of the Queen's sister, Princess Margaret, will also be in attendance, along with three of Prince Philip's German relatives - Bernhard, the Hereditary Prince of Baden; Donatus, Prince and Landgrave of Hesse; and Prince Philipp of Hohenlohe-Langenburg.
The Countess Mountbatten of Burma, previously known as Lady Romsey and later Lady Brabourne - who was Prince Philip's partner when he pursued his sporting hobby of carriage driving - will also be in attendance.
A Downing Street spokesman said Prime Minister Boris Johnson would watch the funeral on television from his country residence Chequers.
Meanwhile, Heathrow Airport said no planes would land or take off for six minutes to coincide with a national minute's silence at 15:00 BST on Saturday, to mark the start of the funeral.
The full order of the funeral service, which will be conducted by the Dean of Windsor, will be released on Friday evening.
The 30 people attending the funeral
- The Queen
- The Prince of Wales
- The Duchess of Cornwall
- The Duke of Cambridge
- The Duchess of Cambridge
- The Duke of Sussex
- The Duke of York
- Princess Beatrice
- Edoardo Mapelli Mozzi
- Princess Eugenie
- Jack Brooksbank
- The Earl of Wessex
- The Countess of Wessex
- Lady Louise Windsor
- Viscount Severn
- The Princess Royal
- Vice Admiral Sir Timothy Laurence
- Peter Phillips
- Zara Tindall
- Mike Tindall
- Earl of Snowdon
- Lady Sarah Chatto
- Daniel Chatto
- Duke of Gloucester
- Duke of Kent
- Princess Alexandra
- Bernhard, Hereditary Prince of Baden
- Prince Donatus, Landgrave of Hesse
- Prince Philipp of Hohenlohe-Langenburg
- The Countess Mountbatten of Burma
How to follow the funeral on the BBC TV and radio
HRH The Duke of Edinburgh Remembered: BBC One, Friday 16 April, 19:00-20:05
The Funeral of HRH The Prince Philip, Duke of Edinburgh: BBC One, Saturday 17 April, 12:30-16:20 and 20:10-21:10
The funeral will also be broadcast on Saturday 17 April from 14:00-16:10 on Radio 4 and Radio 5 Live, BBC World Service English, BBC Radio Scotland and BBC Radio Ulster.
It will also be broadcast on BBC Radio Wales and BBC local radio with some variation in start times.