We're sorry to tell you that Spike TV's Deadliest Warrior series was cancelled after the third season.
According to star Geoff Desmoulin, via his Twitter account, the series "was just too expensive to produce. The pressure to be historically, and scientifically accurate comes at a price!"
The series first aired on April 7, 2009, with an episode titled Gladiator vs. Apache, and the series finale aired on September 14, 2023 with an episode titled Vampires vs. Zombies.
A pair of games based on the series, titled Deadliest Warrior Games, has just been released as a compilation - Deadliest Warrior: Ancient Combat.