Estelle and Leonore take centre stage

It was granddad's 69th birthday but his two littlest ladies completely stole the show. King Carl XVI Gustaf is used to being surrounded by women - his royal family is one of the most female heavy in Europe - but in 2015 he really met his match as Princess Estelle and Princess Leonore put on a performance of cuteness that may take some years to get over.

Ready for their close up - Estelle and Leonore hold hands on their granddad's birthday 

Number two and number five in the line of succession made their first appearance of the day in the courtyard of the Royal Palace where they listened as the king was given a mini birthday concert by the Army Guard. The monarch stood on a dais with his only son, Prince Carl Philip, at his side while his consort, Queen Silvia and his heiress, Crown Princess Victoria were joined by Princess Madeleine, Princess Estelle, Princess Leonore and the royal bride to be, Sofia Hellqvist. And while the princess in waiting got plenty of attention it was her fiance's nieces that really made their mark.

Estelle, by now a veteran of royal events at the age of three, looked like she was having a great time, smiling and taking everything in. Little Leonore, now 14 months old and fresh from an audience with the Pope, started off in mummy's arms and had a cuddle with auntie Sofia but ended up on her pins and holding hands with her cousin. The future of Sweden's royal family linking arms was an image for the history books.

King Carl XVI Gustaf of Sweden on his birthday

It got better. The royal family of Sweden isn't that big but their balcony is even smaller and it's looked pretty crammed in years gone by as the House of Bernadotte has grown. This year it promised to burst at the seams but the king and queen had an easy solution for that. Carl XVI Gustaf and Silvia just took their granddaughters out with them to meet the crowds. The result was picture perfect.

The King and Queen of Sweden with their two granddaughters, Estelle and Leonore, on Carl XVI Gustaf's birthday, April 30th 2015

Estelle posed with granny and granddad, so did Leonore and we even got the two girls together. But perhaps the most striking and symbolic photo of the day was the one taken of Carl XVI Gustaf, King of Sweden with Princess Estelle, born to one day inherit his throne, These two generations of Swedish royalty stood briefly alone together before their fellow countrypeople and the result was an image that will last for decades - two generations, one crown, a shared destiny. History in the making.

One kingdom, one monarch, another in waiting - a photo for the royal history books in Sweden