The 94-year-old made her first major appearance for the event since withdrawing from public life during the outbreak.
A small number of Welsh Guardsmen and military musicians took part in the ceremony, replacing the traditional Trooping the Colour.
It is only the second time in the Queen’s 68-year reign that the parade has not gone ahead in London as usual.However, the ceremony did air in full on BBC One (and is available to watch on iPlayer).
What normally happens?
The Queen was actually born in April but her official birthday is celebrated in June.
A much larger ceremony involving Trooping the Colour usually takes place in London.
The only other time the event was cancelled was in 1955, due to a national rail strike.
Due to the social distancing that isn’t possible.
Thousands of royal fans flock to Buckingham Palace to watch the exuberant honouring of the monarch. However, restrictions mean they cannot attend this year.
Nonetheless, the Queen is believed to have been keen to 'return to work' for over a month.
Why are the Queen's birthday celebrations different this year?
Social distancing rules were put in place for those who marching and performing drills due to the lockdown.
Guardsmen normally stand shoulder-to-shoulder had to stand 2.2m apart to follow guidelines.
Social distancing was particularly relevant when regarding how the soldiers could march.
BBC coverage host Huw Edwards reflected at one point: "In the traditional parade, the regimental Sergeant Major would be taking the colour from the Colour Party and handing it to the Ensign.
"But due to the social distancing that isn’t possible so the Ensign is carrying the colour for the entirety of the ceremony."
How did people watching the ceremony react on social media?
Among the many birthday wishes made to the Queen, many other Twitter users expressed their relief that the ceremony had gone ahead.
"Wonderful event - watch it every year. So pleased it is taking place (with social distancing) despite everything," tweeted one person.
"Really enjoying. Thank you everyone for a wonderful musical, celebratory morning at this hard time," echoed another.
The Queen’s Official Birthday ceremony is underway at Windsor Castle - are you watching the coverage? 💂🥁 pic.twitter.com/aih0fuZz5y
— The Royal Family (@RoyalFamily) June 13, 2020
A third person wrote: "Lovely, nobody puts on a show as good as we do."
And another royal fan added: "Watching and feeling proud and privileged to have a monarch who is duty led and inspiring to our nation.
"It is so reassuring in these strange and troubled times to see Her Majesty as stalwart as she ever has been. Long may she reign."
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