On December 18, the official Instagram account of the Prince and Princess of Wales posted a photo of Duchess Kate celebrating Christmas in 1983, when she was just one year old.

The post was intended to promote Shaping Us, a campaign launched by William and Kate to raise awareness about the importance of the first five years of a child's life. According to the Welsh couple, this period plays a crucial role in shaping a person's future personality.

The previously unpublished photo has attracted hundreds of thousands of likes and countless comments. Many online users expressed their delight at the resemblance between young Kate and her youngest son, Prince Louis (5 years old).

Fans commented, “I see Prince Louis,” “I think we can all agree that Louis is the male version of his mother. The Middleton genes are strong,” “Oh my gosh, this is Louis,” “Definitely Louis,” “Okay, this is Louis. Louis is Catherine,” “Louis is her lookalike,” “You’re lying, this is Louis,” “It looks like a copy and paste,” “So cute, you can see little Prince Louis in this photo. He inherits a lot of the Middleton family’s traits.”

Prince Louis is the youngest child of Prince William and Duchess Kate, after Prince George (10) and Princess Charlotte (8). He was born in April 2018.

The young royal is known for his playful personality and often becomes the center of attention at public events. He recently made headlines when he blew out his sister's candles at a ceremony at Westminster Abbey in London on December 8.

After comparisons of Duchess Kate and Louis' appearance went viral, social media users began to speculate which adult members of the British royal family the current little princes and princesses resemble.

Photos of Prince George at the December 8 event are said to show that he is increasingly resembling his father, Prince William.

Royal fans believe that Princess Charlotte bears a strong resemblance to her grandmother, Princess Diana, while some believe that William and Kate's daughter looks like Queen Elizabeth II.