The royal and her husband were joined by members of their family on Friday at Chapel Royal, St James’ Palace, for a private ceremony. While no other details have been shared, it is likely guests included Beatrice's sister Princess Eugenie and their mother, Sarah Ferguson.
WATCH: Princess Beatrice and Edoardo Mapelli Mozzi welcome first child
Many royal fans were left wondering why Beatrice didn't christen Sienna back in November alongside Eugenie's son August and Zara and Mike Tindall's son Lucas, who were baptised together in the presence of the Queen at the Royal Chapel of All Saints in Windsor.
But Sienna was just two months old at the time, and it is likely she may have wanted to wait a little longer to christen her child, following in the footsteps of her mother – who christened Beatrice when she was four months and Eugenie when she was nine months.
Beatrice and Edoardo welcomed Sienna last September, with a statement from Buckingham Palace confirming the news.
Beatrice and Edoardo christened Sienna in a private ceremony
It read: "Her Royal Highness Princess Beatrice and Mr Edoardo Mapelli Mozzi are delighted to announce the safe arrival of their daughter on Saturday 18th September 2021, at 23.42, at the Chelsea and Westminster Hospital, London.
"The baby weighs 6 pounds and 2 ounces. The new baby's grandparents and great-grandparents have all been informed and are delighted with the news. The family would like to thank all the staff at the hospital for their wonderful care.
"Her Royal Highness and her child are both doing well, and the couple are looking forward to introducing their daughter to her big brother Christopher Woolf."
The couple shared this photo to announce Sienna's birth
Shortly after the birth, a family friend of the couple explained the sweet meaning behind the name Sienna.
"They were looking for an Italian name which started with an S for Sarah, to honour the Duchess [Sarah Ferguson], and also reflected the golden rust colour of both the Duchess's hair colour and Beatrice's, which the new baby shares," they said.
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