Queen Elizabeth's Platinum Jubilee: Queen thanks public for celebration

A festive spirit is in the air in the U.K. as it prepares to celebrate its monarch, Queen Elizabeth II, with a once-in-a-lifetime event.

In London, six portraits of the queen are being projected onto the iconic Marble Arch, a 19th century ceremonial gate originally designed as the state entrance for Buckingham Palace, which now resides at the nearby Hyde Park.

Another landmark, Stonehenge, in Wiltshire, England, is also displaying portraits of the queen, one from each decade of her reign.

Collector’s items are also popular for this historic celebration, from souvenir mugs and medals to stamps, handkerchiefs, socks and even a limited-edition Barbie doll.

The Royal Mint has also released a special coin collection to mark the queen’s 70th anniversary.

Queen Elizabeth had a bumpy flight back to England ahead of the four-day public celebration of her Platinum Jubilee. The queen’s flight from Scotland -- where she had enjoyed a four-day break at her Balmoral estate -- had trouble landing due to lightning.

“The Queen’s flight was delayed due to a lightning storm, all the correct procedures were followed and there were no safety concerns,” a Buckingham Palace spokesperson said in a statement.

The queen was later photographed being driven to Windsor Castle.

Queen Elizabeth is expected to make her first public appearance for the festivities on Thursday, when she joins members of the royal family at Trooping the Colour, her annual birthday parade.

First lady Dr. Jill Biden sent well wishes to Queen Elizabeth ahead of the monarch’s Platinum Jubilee celebrations.

The message from Dr. Biden aired exclusively Wednesday on “Good Morning America.”

“Your Majesty, Joe and I wish you a wonderful celebration of your Platinum Jubilee,” Biden said. “Congratulations on 70 years of service to the United Kingdom and Commonwealth, and thank you for your enduring friendship with the American people.”

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What Queen Elizabeth means to America

First lady Jill Biden shares a special message for the monarch ahead of the Platinum Jubilee.

Last year at Windsor Castle, Biden and her husband, President Joe Biden, visited Queen Elizabeth, who has met nearly every U.S. president elected during her 70-year reign.

A jubilee celebrates a significant milestone in the life and reign of a monarch.

Over the course of her 70 years on the throne, the longest reign in Britain’s history, Queen Elizabeth II has celebrated five jubilees prior to this one, her Platinum Jubilee.

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A look at past jubilees as Queen Elizabeth marks 70 years on the throne

ABC News has covered every celebration, from the Silver Jubilee celebrating 25 years of her reign in 1977 to the floating musical parade of the Diamond Jubilee in 2012.

In 1977, the queen celebrated her Silver Jubilee, marking 25 years on the throne. She and her husband, the late Prince Philip, marked the occasion by traveling tens of thousands of miles throughout the U.K. and the Commonwealth on jubilee tours.

Fifteen years later, in 1992, Elizabeth celebrated her Ruby Jubilee, marking her 40th anniversary as a monarch. She did not host public jubilee events that year, which she later described in a speech as “Annus Horribilis,” or “horrible year,” due to a fire at Windsor Castle and the end of three of her children’s marriages.

In 2002, Elizabeth celebrated her Golden Jubilee, marking 50 years on the throne. The queen and Philip again traveled throughout the U.K. and the Commonwealth for a celebration that culminated with a concert at Buckingham Palace.

In 2012, the queen marked her Diamond Jubilee with a boat pageant on the River Thames. The pageant featured hundreds of boats and an estimated 1 million people watching along the river.

In 2017, the queen celebrated her Sapphire Jubilee, marking 65 years on the throne, the first time a British monarch had celebrated a 65-year reign. A series of royal gun salutes commemorated the anniversary across London.