KSI, whose real name is Olajide Olayinka Williams Olatunji, is one of the most well-known British internet personalities. Since 2009, KSI has produced widely popular gaming and vlog content for his YouTube channel, expanding into a career as a professional rapper, musician, and author in 2015. In 2018, he began training to be an amateur and professional boxer, culminating in high-profile fights against YouTube personality Logan Paul in 2018 and 2019. To this day, KSI remains one of YouTube’s most prominent renaissance men, churning out top-notch content both as an individual creator and as a member of the Sidemen, a collective of British YouTubers that he co-founded. His name comes from the name of a prominent Halo clan that KSI joined as a teenager, and stands for “Knowledge, Strength, Integrity.” Nowadays, of course, KSI is much more well-known than his eponymous Halo clan, though the clan is still active.