The Nine Titans were nine Titan powers that had been passed down through the Eldian people for nearly 2,000 years after the death of Ymir Fritz until the death of Eren Yeager, with each having their own name. The nine Titan powers were the Founding Titan, the Armored Titan, the Attack Titan, the Beast Titan, the Cart Titan, the Colossus Titan, the Female Titan, the Jaw Titan and the War Hammer Titan.
History: Around 2,000 years ago, Ymir Fritz obtained the power of the Titans and became the first Titan, which later came to be known as the Founding Titan. Thirteen years later, she died and her power was then divided between her three daughters who had been forced by their father to consume her remains. Eventually, the powers would split further into the individual Nine Titans, which were subsequently inherited by nine of her descendants.
Trivia: Many transformed Titan forms are modeled after mixed martial artists. For instance, the Armored Titan is modeled after and the Attack Titan is modeled after . Grisha Yeager consuming the Founding Titan and Eren Yeager consuming the War Hammer Titan are the only known cases where a person inherits one of the Nine Titans while already having one.
Source: Nine Titans, available under CC BY-SA 3.0.