It was taken at Kensington Palace by one of the couple's favourite and most trusted photographers, Matt Porteous, and marks an important new stage in the young royal's life.
Kate, 44, met patients at one of Europe's leading cancer centres to 'highlight the healing power of holistic care alongside clinical care,' according to Kensington Palace.
The Princess of Wales travelled to the Christie NHS Foundation Trust in Manchester to 'highlight the healing power of holistic care alongside clinical care', according to Kensington Palace.
Taken earlier this month during the family's Easter break, the sweet clip was posted on Kensington Palace's social media accounts with the message: 'Thank you for all the birthday wishes.'
In celebration of Louis' eighth birthday today, Kensington Palace have released a new portrait of the young prince that bears a striking likeness to Britain's future King.