It's not everyday that a Princess is born. To honour the arrival of William and Kate's baby girl, some of London's most iconic landmarks turned pink on the evening of Saturday 2 May to celebrate the newest addition to the British royal family in style.
As soon as it was announced that the Duchess of Cambridge, née Kate Middleton, had given birth to a daughter, the BT Tower in Fitzrovia displayed a pink rolling banner declaring, 'It's a girl!'.
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The London Eye colourfully acknowledged the new Princess' arrival
Westminster Council then revealed how the capital would be acknowledging the royal brith, tweeting: "Congratulations to the Duke and Duchess of Cambridge, landmarks in Westminster will be turning pink tonight to celebrate the new #RoyalBaby."
Sure enough, as it grew darker later in the day, Tower Bridge, the London Eye and The Golden Jubilee Bridge were flooded with pink light.
Tower Bridge was aglow with pink light
Just a stone's throw from the Lindo Wing at St Mary's Hospital where the little Princess made her way into the world, The Hilton Hotel in Paddington and The Merchant Square Fountain in Paddington Basin also lit up.
The fountains in Trafalgar Square, which had turned blue when Prince George was born on 22 July 2013, were coloured pink for the future King's little sister.
William and Kate presented their baby girl at St Mary's Hospital in Paddington
It wasn't just in London that the news of William and Kate's new arrival was celebrated with vibrant pink lights; Belfast's magnificent City Hall in Donegall Square also had a rosy glow.
Elsewhere in the UK it was the Queen's choice of clothing that seemed to pay a colourful tribute to her new great-grandchild. In a nod the baby girl's arrival, Britain's monarch stepped out in North Yorkshire sporting a vibrant fuchsia coat and matching hat.
Online, the nation was abuzz with messages of congratulations for new parents William and Kate and hashtags including '#RoyalBaby' and '#RoyalBabyGirl' quickly began to trend.
"Congratulations to the Duke and Duchess of Cambridge on the birth of their baby girl," tweeted Prime Minister David Cameron. "I'm absolutely delighted for them."
Further afield, sailors on board HMS Lancaster posed for an aerial photograph spelling out the word 'sister', directed at new big brother George.