Julius Caesar is a Caesar Kingdom hero and requires 500,000 prestige to unlock.
Unit type - Elite Mounted Archers: High critical strike rate
Gambit - Caesar's Sword: Unique Caesar skill. Massively increase your army's Morale. Hits an enemy for gambit damage and gives all heroes besides Caesar 120 morale.
Because Caesar's Sword provides +120 moral then it is very easy for a Caesar Octavian combo to regularly over-pump other gambit heros 220+ gambit strikes. Using Cleopatra, Octavian and Caesar acting before two primary attacking gambit heros, such as Titus, Nero or Hector means only two high level mounts are needed to be utilized to deliver powerful gambit attacks across multiple targets.
Caesar starts with 1540 units and gains 38 per level.