Louis is the third name of Prince George and Prince William's fourth name as Prince Charles selected it as an homage to his mentor and friend Lord Louis Mountbatten, the Duke of Edinburgh's uncle.
He is the third child from the Duke and Duchess of Cambridge and is the fifth in line to the throne. In their wedding in 2011, Kate had to repeat William's full name when reciting her vows.
The choice also honors Louis Mountbatten, Charles' great-uncle and beloved mentor, who was killed by an Irish Republican Army bomb in 1979.
Charlotte took centre stage on the day her baby brother Prince Louis was born when she visited him in hospital. As for the littlest and newest royal's other names, he shares Arthur and Charles with both his father and his grandfather, Prince Charles, who is Charles Philip Arthur George.
The royal daughter had some practice as a bridesmaid for her aunt Pippa Middleton, who Wednesday last May.
'Colleagues kept saying, "Louis, you've got the same name as the royal baby!",' said the operating theatre assistant from Cheltenham. Among the British bookies' favorite picks were Arthur, James, Albert and Phillip.
Twitter users with personal connections to the fresh prince's names offered peals of joy.
Although the TV cameras might have stopped rolling, the people of Britain are still without an answer on how to pronounce the name of their new overlord.
Former One Direction star Louis Tomlinson - a noted devotee of the Adidas brand - tweeted: "Young Louis welcome to the world".
"Whatever circumstances you are born into or give birth under, it will never ever eradicate the complete turmoil and exhaustion that birthing a baby is for any mother, so I hope that Catherine finds some downtime to simply just be whatever shape she needs to be in to be able to care for a new baby". "The Adidas tracksuit is in the post!"
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