BBC Newsround takes a 90-second look back at some of the major events that have happened during the Queen's 90 years.

To see some of those highlights, click here. 

The man in charge of the "principal beacon" has said "the eyes of the world will be on Windsor" this evening. 

Nick Day of the Crown Estate said that the beacon which will be lit by the Queen at 19:00 BST should glow with her initials and the number 90. 

After that beacon is light, others will follow across the country and overseas. 

With Windsor Castle being the location of most of the Queen's 90th birthday celebrations, BBC correspondent Sarah Campbell reports on why it is so special to the Queen.  

To watch that video, click here. 

Thousands of people lined the streets as the Queen left Windsor Castle to meet them with the Duke of Edinburgh. 

BBC correspondent Daniela Relph has been talking to some of them.

To see the report, click here. 

The Queen will later light a beacon in Windsor - to be followed by people following her example with more than 900 others across the UK and overseas. 

Among those locations will be Corfe Castle in Dorset, where five beacons will be lit. 

Ian, who is carrying out the final preparations, said they would light despite the windy conditions. 

"We have two years of practice with a few Christmases, we know it'll work."  

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Image source, Conrad Engelhardt

Conrad Engelhardt, an artist from Shoreditch in London, made this portrait of the Queen in celebration of her 90th birthday. 

It is made up of more than 4,000 wine corks collected from restaurants across London. 

Conrad said all of the colours came from wine stains on the corks and the corks themselves and were not coloured in any way.

Here are some highlights from the BBC's radio coverage of the Queen's historic birthday walkabout in Windsor. 

BBC Monitoring

The Queen's 90th birthday has attracted considerable international media coverage, although it does not often make the newspaper front pages outside Commonwealth countries. 

To read what the newspapers have been saying about the UK's longest-reigning monarch, click here. 

Earlier, accompanied by the Duke of Edinburgh, the Queen arrives to unveil a plaque marking The Queen’s Walkway - a 6.3km trail that links 63 significant points in the Berkshire town of Windsor.

The trail was designed to commemorate the moment, on 9 September last year, that the monarch broke the record held by her great-great-grandmother Queen Victoria, by being on the throne for 63 years and seven months.

Lauren Turner
BBC News reporter

Image source, PA

This was, in many ways, an ordinary working day for the Queen. 

Unveiling a plaque, meeting flag-waving members of the public on a walkabout, being presented with a bouquet of flowers - these are things she has done thousands of times. 

But the crowds weren't going to let her forget that this day, her 90th birthday, was something out of the ordinary.

Some had been waiting for hours - some for days - to catch a glimpse of the Queen on the day she became the nation's first-ever nonagenarian monarch.

The crowds were 10 deep in places, with locals from Windsor desperate to see their neighbour standing alongside those from Canada, the US and Japan. 

They came wearing Union Jack ties and wigs, and tights embellished with crowns.

As the Queen and Duke of Edinburgh walked the short distance from Windsor Castle, a spontaneous rendition of Happy Birthday rang out - and it wouldn't be the last.

"Oh, I can see her!" someone shouted out, spotting a glimpse of her lime green hat.

There were three cheers for the Queen and excited applause as she passed the crowds on her way to the Guildhall.

One woman who has lived nearly as long as the Queen summed up the atmosphere. 

Gwen Tarr, 88, who says she is "Windsor born and bred", said: "It was so lovely. 

"I just wanted to celebrate the day with her and wish her a happy birthday - and many more birthdays to come."

To mark the royal walkabout in Windsor, Radio Berkshire interviewed a number of the county's nonagenarians. 

Patricia Anderson shares the same birthday as the Queen, and she said she has "great admiration" for her. 

Image source, Getty Images

A 62-gun salute has been fired at the Tower of London as part of the birthday celebrations. 

Actress Joan Collins told the BBC people were able to "see through celebrities", which was why "some of them only have their 15 seconds (of fame)". 

But she said of the Queen:

Nadiya Hussain earlier spoke to the BBC about making a cake for the monarch.

The 2015 Great British Bake Off winner, who met the Queen when she cut her creation, said the experience was one of her "proudest moments". 

"It was over really quickly, so I'm reliving it again now in my head. That actually happened, I met the Queen!"

She said the process of making the orange drizzle cake had been "quite relaxing". 

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