Princess Charlotte is Prince William and Kate Middleton's second child. Will Warr/Kensington Palace/Handout via Reuters 2025-05-22T12:42:01Z Save Saved Read in app This story is available exclusively to Business Insider subscribers. Become an Insider and start reading now. Have an account? Princess Charlotte turned 10 in May. As Prince William and Kate Middleton's second child, she's third in line for the British throne. Although her life is mostly private, Charlotte shows peeks of her personality at royal engagements. The roles of "heir" and "spare" have haunted royal siblings for centuries.The very existence of secondborn children in the British royal family is tied to a crown they'll ideally never hold, as they serve as backups to the direct heirs to the throne. Still, spares can play a critical role in the monarchy, as was the case for King George VI, who became monarch in 1936 after his brother abdicated. Even as it adapts to the modern world, the heir and spare dynamic continues to shape the monarchy, as evidenced by the title — and contents — of Prince Harry's 2023 memoir.In the latest generation of royals, Princess Charlotte is the spare to Prince George's heir. However, at just 10, Charlotte is already breaking the mold she was born into, charting a new path for the royals.Here's everything to know about Princess Charlotte.Princess Charlotte joins the royal familyIn a press release on September 8, 2014, Kensington Palace announced that Kate Middleton was expecting her and Prince William's second child. The statement also said that Kate had hyperemesis gravidarum, as she did with her first pregnancy, and would be missing an engagement in Oxford that day as a result.Charlotte was born on May 2, 2015, at 8:34 a.m., at the Lindo Wing of St Mary's Hospital in London, just like Prince George, Prince William, and Prince Harry were. Kate Middleton and Prince William posed with Princess Charlotte outside the hospital the day of her birth. Mike Marsland/Getty Images William and Kate debuted their daughter to the world during a photocall on the hospital's steps the same day she was born. Kate posed for photos on the hospital's steps after each of her children's births, following in Princess Diana's footsteps.Charlotte's full name is Charlotte Elizabeth Diana, and at the time of her birth, her title was Her Royal Highness Princess Charlotte of Cambridge.Charlotte is the feminine version of Charles, her grandfather's name. Her middle names nod to her great-grandmother, Queen Elizabeth II, and her late grandmother, Princess Diana.At her birth, Charlotte was fourth in the royal line of succession, behind her grandfather, father, and older brother.Queen Elizabeth II ensured Charlotte's position in the line wouldn't be affected by her gender through the Succession to the Crown Act in 2013. The act changed a long-standing rule that male siblings superseded their female siblings' position in the line to the throne. If it hadn't been passed, Prince Louis' birth in 2018 would have moved Charlotte down the line of succession. Princess Charlotte began attending Lambrook School in September 2022. Jonathan Brady/Pool/Getty Images After Queen Elizabeth died in 2022, King Charles III made William the Prince of Wales, so his daughter's title became Princess Charlotte of Wales. Likewise, she moved up to third in line for the throne after her great-grandmother's death. Princess Charlotte's royal lifeAccording to the royal family's website, the princess was christened by the Archbishop of Canterbury at St Mary Magdalene Church in Sandringham in July 2015. Prince George was photographed peering into her stroller at the ceremony.Charlotte has five godparents, including Kate's cousin, Adam Middleton. Prince George looked into his sister Princess Charlotte's pram after her christening in July 2015. Matt Dunham/Reuters Kate and William released a few photos of the princess as a baby, but she didn't join her parents on an overseas tour until she was 16 months old, in September 2016, when she went with her family to Canada.Charlotte and Kate wore color-coordinating outfits throughout the trip, a tradition they've kept up throughout Charlotte's life.Charlotte became a big sister in 2018 when Prince Louis was born, completing the Wales family. The princess attended Thomas's Battersea school in London from 2019 to 2021, and she began attending the Lambrook School after the Wales family relocated to Windsor full-time in 2022. Princess Charlotte has appeared on the Buckingham Palace balcony during Trooping the Colour. Karwai Tang/WireImage/Getty Images William and Kate have balanced their children's royal roles with their privacy as they've grown up, allowing them to attend only a handful of royal engagements each year and releasing photos of them for special occasions, like birthdays or holidays.Charlotte appears annually at Trooping the Colour and the royal family's Christmas walk at Sandringham. She has also been present for milestone moments for the royals, like Queen Elizabeth's funeral in September 2022 and King Charles' coronation in May 2023.Charlotte often appears to be the most comfortable of her siblings at royal engagements, speaking with members of the public and even correcting her brothers on royal protocol.The young princess has also been spotted attending less formal events from time to time, showing off a more authentic side of the royal family in the process.Kensington Palace shared photos of Charlotte at the Eras Tour in June 2024, smiling with William, George, and Taylor Swift. She also joined her mother at Wimbledon in July 2024, accompanying Kate to the first solo engagement she attended after announcing her cancer diagnosis. Princess Charlotte joined Kate Middleton at Wimbledon 2024. Karwai Tang/WireImage/Getty Images Charlotte's comfort in the spotlight, even compared to her older brother, differentiates her from royal "spares" of the past, who are often relegated to the role of wild child in comparison to the heir's steadiness. She seems calm and competent at public events, and she may already be taking after her great-aunt Princess Anne, whose steadfastness is an asset to King Charles.At only 10, it's clear Princess Charlotte's future in the royal family is bright.