EXCLUSIVE PICTURES FROM QUEEN ELIZABETH'S 90TH BIRTHDAY

The Queen has lit the first of more than 900 beacons lighting up across the UK and overseas as part of her 90th birthday celebrations.

Prince Philip, the Prince of Wales and Duchess of Cornwall then joined the monarch at a private dinner in Windsor Castle.

Earlier, cheering crowds lined the streets in Windsor as the Queen took part in a walkabout.

On Twitter, the Queen thanked senders of "#HappyBirthdayYourMajesty" tweets.

In another tweet, the Queen said: "I send my best wishes to those who are celebrating their 90th birthday... on this shared occasion, I send my warm congratulations to you." 

At the lighting of the beacon in Windsor, the Prince of Wales, referring to his mother, said: "I find it very hard to believe that you've reached your 90th year and I suddenly realised the other day that I have known you since you were 22 years old.

"But this, ladies and gentleman, is a very special occasion and this beacon that her majesty is about to light will also represent - as it lights other beacons across the nation - the love and affection with which you are held throughout this country and the Commonwealth.

"So can we wish your majesty a special and the most happiest of birthdays on this occasion."

Members of the Army cadet force have taken beacons to the top of the highest peaks of England, Scotland, Wales and Northern Ireland.

Some of the beacons are specially built gas-fuelled structures, while others are traditional bonfires or braziers on top of tall wooden posts. 

Earlier, Royal gun salutes were fired from each of the UK's capital cities as the Queen met crowds of well-wishers in Windsor.

The Queen, who was accompanied by the Duke of Edinburgh, was presented with a birthday cake at the Guildhall by the Great British Bake Off champion Nadiya Hussain, who had created an orange drizzle cake with a butter cream and marmalade filling. 

The monarch also unveiled a plaque marking The Queen's Walkway - a 6.3km trail that links 63 significant points in Windsor.

The trail was designed to recognise the moment on 9 September 2015 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.

Prime Minister David Cameron said the Queen had been "a rock of strength for our nation" and the Commonwealth, as he and fellow politicians paid tribute in the House of Commons.

Mr Cameron said: "Her Majesty The Queen has lived through some extraordinary times in our world.

"From the Second World War... to the rations with which she bought the material for her wedding dress. 

"From presenting the World Cup to England at Wembley in 1966, to man landing on the moon three years later. From the end of the Cold War to peace in Northern Ireland. 

"Throughout it all, as the sands of culture shift and the tides of politics ebb and flow, Her Majesty has been steadfast - a rock of strength for our nation, for our Commonwealth and on many occasions for the whole world." 

On Friday, US President Barack Obama and First Lady Michelle Obama will be joining the Queen for lunch at Windsor Castle.

Every year the Queen celebrates two birthdays, with her actual birthday on 21 April and her official birthday on a Saturday in June. 

Celebrations of her official birthday this year take place from 10-12 June.

Source:BBC