Prince William and Prince Harry are the cutest kids in THIS throwback photo with mum Diana

To announce William's new initiative, Kensington Palace shared an Instagram post featuring a throwback photo of the royal brothers playing on a fire truck as young little boys.

By Pinkvilla Desk

Updated on Sep 11, 2019 | 08:36 AM IST | 3.4M

Prince William had the sweetest Throwback Tuesday post to share on the official Kensington Royal Instagram page. The throwback featured him and his younger brother Prince Harry as well as their mum Princess Diana. Dating back to 1988, Prince William shared the post as part of the #999DayUK, marked to celebrate the contribution of police, fire and emergency medical services. The Duke of Cambridge also launched a texting service aimed at helping physical and mental health support to members of the UK’s fire and rescue services.

To announce the initiative, Kensington Palace shared an Instagram post featuring a throwback photo from 1988 of the royal brothers playing on a fire truck as young little boys. Princess Diana can also be seen in the background along with their cousins Peter and Zara Phillips. In the picture, the brothers can be seen in matching light blue coats and gold firefighter helmets sitting atop a vintage fire engine.

The caption read, "The first photograph in this post is of The Duke of Cambridge and The Duke of Sussex and their mother Diana, Princess of Wales, with their cousins Peter Phillips and Zara Tindall in the yard of the Old Fire Station in the grounds of Sandringham House in 1988." Check out the adorable picture below:

Today marks #999DayUK, when we celebrate and say thank you to our incredible Police, Fire and Emergency Medical services and all our specialised emergency services for all that they do to keep us safe. The first photograph in this post is of The Duke of Cambridge and The Duke of Sussex and their mother Diana, Princess of Wales, with their cousins Peter Phillips and Zara Tindall in the yard of the Old Fire Station in the grounds of Sandringham House in 1988. On 999 Day later today The Duke will visit @TheFirefightersCharity at Harcombe House in Devon to hear about the support that the centre provides to members of the fire and rescue service and their families, and meet representatives from across the emergency services sector. On the extraordinary work of our emergency services, The Duke of Cambridge said: "As a society, we owe our wellbeing, and indeed our lives, to the men and women in our emergency services who work tirelessly to protect us in some of the most difficult circumstances. It is only fitting that we should recognise the vital role that they play, and pay tribute to the bravery and dedication of those who have made the ultimate sacrifice for their communities." 999 Day begins annually at 9am on the 9th September (the 9th hour of the 9th day of the 9th month) and is held to pay tribute to the invaluable work that is carried out by the emergency services and responders. Getty images / Press Association

Prince William is a father to three kids. Whereas, Prince Harry recently embraced fatherhood when baby Archie was born in May this year. William and Harry's relationship often makes headlines amid the royal rift drama.