He initially set out to raise £10k for charity after being diagnosed with terminal cancer aged just 15, but ended up making £3m for The Teenage Cancer Trust after news of his condition went viral on social media.
Stephen drew up a bucket list of things he wanted to do before he died, which included getting a tattoo, playing the drums in front of a massive crowd and hugging an elephant.
Numerous celebs also championed Stephen’s cause, including Russell Brand, Jason Manford and Clare Balding.
Earlier this month, David Cameron visited Stephen in hospital and praised his ‘incredible’ efforts to help other cancer sufferers.
Speaking on her son’s Facebook page, Stephen’s mum spoke of her devastation at her son’s death.
“My heart is bursting with pride but breaking with pain for my courageous, selfless, inspirational son who passed away peacefully in his sleep in the early hours of this morning,” she wrote.
“The ongoing support and outpouring of love for Stephen will help greatly at this difficult time, in the same way as it helped Stephen throughout his journey.”
Image credit: Facebook