While the Duke and Duchess of Sussex have named their daughter after her great-grandmother, their new baby's name has strong religious roots.
Lilibet means "God's promise" and is also related to the Hebrew name Elizabeth which means "God is my oath." Elizabeth was also the mother of John the Baptist in the bible.
Lilibet is the Queen's family nickname and was first used by Queen Elizabeth when she was unable to pronounce her name correctly as a toddler while her late husband, Prince Philip, often referred to the Queen as Lilibet.
As an adult the Queen also used the nickname herself ending a note to her grandmother Queen Mary, with 'Love from Lilibet.'
Lilibet "Lili" Diana was born at 11.40am on Friday June 4 at Santa Barbara Cottage Hospital in California weighing in at 7lb 11oz. She is sister to two-year-old Archie, the Duke and Duchess of Sussex's first child.
In a message of thanks on their Archewell website, Harry and Meghan said: "On June 4, we were blessed with the arrival of our daughter, Lili.
"She is more than we could have ever imagined, and we remain grateful for the love and prayers we've felt from across the globe.
"Thank you for your continued kindness and support during this very special time for our family."
The Sussex's press secretary confirmed the baby had been named Lilibet "Lili" Diana Mountbatten-Windsor.
She added: "Both mother and child are healthy and well and settling in at home.
"Lili is named after her great-grandmother, Her Majesty the Queen, whose family nickname is Lilibet.
"Her middle name, Diana, was chosen to honour her beloved late grandmother, the Princess of Wales."
Harry had long been expected to honour his late mother Diana, Princess of Wales, who died in a car crash when he was 12.
The couple's spokeswoman added: "The duke and duchess thank you for your warm wishes and prayers as they enjoy this special time as a family."
New-born Lilibet is the Queen's 11th great-grandchild and is eighth in line to the throne.
Additional reporting by PA