In spring 2025, Charlie was diagnosed with non-Hodgkin lymphoma and signed up to take part in the marathon while he was undergoing treatment.
After six rounds of chemotherapy, Charlie was able to finish his treatment and start training.
"They told me in the hospital that I was the first person on that ward who'd signed up to do the marathon whilst still going through treatment.
"Hopefully other people can see me and think he's just an ordinary lad who can do that, but also for myself it's a bit of a challenge to say, 'listen this period of my life is not going to define me in terms of being ill, not in a negative way” he told the BBC, in a recent article.
Teenage Cancer Trust provides specialised nursing care and expert youth support for young people with cancer.
Charlie told the BBC that the charity provided "massive" amounts of support to him and his mum, including funding a recreation room on the ward, which included game consoles so he could play football with his friends when he was well enough.
On completing the marathon, Charlie said: “It was incredibly challenging, but I had loads of friends and relatives there supporting and spurring me on, so it was a fantastic experience.
“My left leg cramped up at 34km and my right at 37km, so the last stretch was incredibly difficult, and I had to walk some sections but made it through in the end with a time of 4:55.”
He added: “The biggest lesson I learned from this experience and my treatment is that you are stronger than you could ever possibly imagine, and sometimes it takes something out of your control to bring that out. Life is and always will be what you make it, so make it a good one.”
So far, Charlie’s marathon has raised over £18,500 for Teenage Cancer Trust and has helped to increase awareness of non-Hodgkin lymphoma. His fundraising page is active for another three weeks, so Charlie hopes to raise as much as possible for the charity.
Charlie is due to graduate from the University in June this year and plans to work at a summer camp in America for two and a half months. Along with his friends, Charlie is deciding on his next fundraising activity.