It's hard to believe that Princess Charlotte is six-years-old today. The second child of the Duke and Duchess of Cambridge was born on May 2nd, 2o15 — how time flies!
In celebration of the little royal's birthday, we take a look back at some of her most adorable moments...
1. The Duke and Duchess of Cambridge show off their newborn

Here, Kate and William are pictured leaving St Mary's Hospital Lindo Wing with their newborn, Princess Charlotte Elizabeth Diana, on Saturday, May 2nd, 2015.
The couple chose to give their daughter the middle name Diana in homage to William's late mother, Princess Diana.
2. Kate Middleton takes a cute picture of the two siblings

Just weeks after their second child was born, the Duke and Duchess released this adorable picture of Prince George with his new sister.
The photo was captured by Kate.
3. Princess Charlotte's christening

Above, Kate can be seen arriving with Princess Charlotte for her christening, which was held at the Church of St Mary Magdalene in Sandringham, Norfolk, on July 5th, 2015.
Charlotte was just two-months-old at the time.
4. Kensington Palace celebrates Princess Charlotte's birthday

The Royal Family celebrated Princess Charlotte's first birthday by sharing this picture of the tot.
Kate took the photo at the family's home in Norfolk.
5. Princess Charlotte is compared to her grandmother

In this picture, which was also taken by the Duchess of Cambridge, Charlotte was compared to her grandmother, the Queen.
Many people thought that the two bore a striking resemblance, as can be seen in some of the comments on the Instagram post.
6. Charlotte and the Duchess of Cambridge are all smiles

Kate is all smiles and laughter with her daughter at a children's party for military families at Government House in Victoria.
This photo was taken during the Royal Tour of Canada in September of 2016.
7. Charlotte makes an appearance at Trooping of the Colour

Above, Princess Charlotte joins her brother and parents on the balcony of Buckingham Palace.
This photo was taken following the Trooping of the Colour in 2017.
8. Princess Charlotte's second birthday

Kate snapped this picture in May of 2017 to celebrate her daughter's second birthday.
How quickly they grow...
9. Princess Charlotte is a bridesmaid!

Princess Charlotte was a bridesmaid at her aunt Pippa Middleton's wedding to James Matthews.
The big day took place at St Mark's Church in Englefield on May 20th, 2017.
10. Charlotte's first day at nursery

Kate also captured her daughter just before her first day at nursery.
Charlotte attends the Willcocks Nursery School in January of 2o18.
11. The birth of her little brother

Princess Charlotte is pictured here with her older brother and father, on their way to meet the newest addition to the family, Prince Louis.
Her younger brother was born on April 23rd, 2018.
12. Princess Charlotte poses with her little brother

This adorable photo of the two little royals was taken on Princess Charlotte's third birthday.
She may still be a toddler in this snap, but the young royal is clearly a doting big sister.
13. Princess Charlotte's fourth birthday

As is custom, Kate took these sweet pictures of her daughter ahead of her fourth birthday.
The snap was taken in the gardens of Kensington Palace.
14. Princess Charlotte attends Prince Harry and Meghan Markle's wedding

Princess Charlotte waves as she attends the nuptials of the Duke and Duchess of Sussex.
Harry and Meghan's big day was held at St George's Chapel, Windsor Castle, on May 19th, 2018.
15. She also attended Princess Eugenie's wedding

Charlotte waves again while she attends the wedding of Princess Eugenie of York and Jack Brooksbank.
The couple's wedding took place in Windsor on October 12th, 2018.
16. Charlotte breaks down in tears at Trooping of the Colour in 2019

Princess Charlotte is seen in tears on the balcony of Buckingham Palace.
This snap was taken as the Royal Family watched the air display at the Trooping the Colour in London in June, 2019.
17. The princess celebrates Christmas at home

The young princess is pictured with her two brothers and her father.
Clearly taken by her mother Kate, this snap was captured as the family celebrated Christmas at their family home in 2019.
18. Princess Charlotte's first day at school

Princess Charlotte can be seen here holding the hand of her mother as she arrives for her first day of school.
The young royal attends Thomas's Battersea in London on September 5th, 2019.
19. Kate Middleton releases four new pictures of Charlotte ahead of her fifth birthday

This photo was taken by talented photographer, Kate.
Clearly, the Duchess has a talent for capturing precious moments.
20. Another Christmas at home

Princess Charlotte celebrates Christmas 2020 with her family.
This heartwarming snap graced the cover of Kate and William's Christmas cards which the couple sent out that year.
21. Princess Charlotte enjoys the great outdoors

Princess Charlotte can be seen here smelling a bluebell at her home in Norfolk,
This sweet photo taken by her mother during the Covid-19 lockdown.
22. Charlotte celebrates her father's birthday

In honour of Prince William's birthday, Kate snapped this cute photo of the three siblings with their father, the Duke of Cambridge.