The year in which the Sidemen formed on October 19th 2013, Since it was the first year for the sidemen popularity was never that high compared to now.
First off It was between Five Youtubers playing GTA 5 consisting of Behzinga, Miniminter, KSI, TBJZL and Zerkaa with some appearances of Callux, AA9Skillz and Eighth Sidemen Member JME(Although Harry didn't join back then.), The Gaming Lemon and even Bateson87!
Later on in November Vikkstar123 joined increasing the members from Five to Six. The Month of November was the start of something special with The Sidemen playing FIFA.
Back then Behzinga was always bullied about his homosexuality and got angry(this was dropped a few months later due to the Sidemen being accused of homophobic bullying.)
Back then GudjonDaniel was actually friends with KSI until his comments in February 2014. Who knows what happened if things turned out differently.
And finally Back then KSI called himself the King of Pink Slips. But that lead to a 4-0 thrashing by Miniminter and was forced to burn a Arsenal shirt(even though Simon said it was not a Arsenal shirt.)