The Head's Together campaign was established by the royal trio, with mental health being a cause close to their heart. It aims to raise funds and help fight the stigma associated with mental health.
"All of us know someone who has been through difficult emotional times, and we know how hard it can be to see a way forward," the Duchess said during her speech. “William, Harry and I feel it is our duty to do what we can, with your help, to shine a spotlight on emotional wellbeing and highlight the support that is out there to prevent or manage the pain at difficult times," she added.
William also gave a speech, where he implored people to stop thinking of mental health as a “dirty word”.
"We all have mental health like we do physical health, good or ill. But not seeking help at those times when it all seems too much, or we are depressed or anxious, can impact the rest of our lives," Prince he said. "Put simply, the three of us want to make asking for help no longer a big deal."
During the event the royals hopped on the iconic London Eye to take a 30 minute tour of the city, where Harry joked about being able to see Granny’s house.