Why Prince Louis' Birthday Has a Special Connection to Big Brother Prince George

Prince Louis is turning 6, but he won't be the only one celebrating on April 23.

Prince William and Kate Middleton’s youngest son was born on April 23, 2018, which happens to be St. George’s Day, the feast day honoring the patron saint of England and protector of the royal family...who happens to share a name with Louis' big brother, Prince George!

St. George is believed to have been a high-ranking officer in the Roman army who was killed for refusing to renounce his Christian faith around 303 AD, Historic U.K. reported. He is famously affiliated with the fable of protecting himself with the sign of the cross to slay a dragon and rescue a princess, according to the Golden Legend, circa 1275.

The saint's feast day is a patriotic occasion in England, though celebrations have waned in popularity since the late 16th century. While St. George’s Day is not a bank holiday (the American equivalent of federal holidays) in the U.K., the feast day has regained popularity in recent years as a day to celebrate English culture and history.

The saint’s symbol flies for patriotic occasions throughout the year, and St. George’s cross is also used as the red and white English flag, which is featured in the tricolor Union Jack flag of the United Kingdom.

Prince William, 41, and Princess Kate, 42, may have named Prince George, 10, in a tribute to Queen Elizabeth’s father. Prince William’s great-grandfather chose King George VI as his regnal name upon his accession in 1936, creating continuity following the reign of his father, King George V. Prince George’s full name is George Alexander Louis — and his parents later used one of his middle names as the moniker for his little brother!

The name Louis is similarly sentimental for the British royal family, as it was the name of Prince Philip’s grandfather, Prince Louis Alexander of Battenberg, and Lord Louis Mountbatten, his beloved uncle who was assassinated by the IRA in 1979. Mountbatten was also a mentor to the future King Charles, who named his eldest son William Arthur Philip Louis in 1982. 

Prince Louis and Prince George most recently stepped out with their parents, the Prince and Princess of Wales, and sister Princess Charlotte, 8, for church at Sandringham on Christmas Day in December 2023.

Last week, the siblings returned to the classroom following a half-term break for the Easter holiday, at the start of which their mom Princess Kate announced that she is undergoing treatment for cancer. The Princess of Wales may have strategically waited to make the public announcement about her health on March 22 until her children were out of school, creating space for the family to have private time together. Prince William and Princess Kate are known to clear their calendars when their kids are off from school, and this instance was likely no different.

"The children are at the center of their world," a friend tells PEOPLE about the Prince and Princess of Wales.

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Prince William returned to work on April 18 and appeared moved when a volunteer at food distribution charity Surplus to Supper surprised him with cards for his wife, Princess Kate, and his father, the King, who have both postponed public-facing duties while receiving cancer treatment.

"Oh, some cards, you’re very kind. Thank you very much," Prince William told volunteer Rachel Candappa when she presented him with well-wishes, in a video shared to X by Lizzie Robinson of ITV.

When Candappa, 71, told William to look after his wife, he placed a hand on her shoulder and said, "I will," The Telegraph reported.