The first Pokémon games - Red and Green - were introduced in Japan on February 27, 1996, immediately taking the world by storm. With a roster of 151 pocket monsters, the franchise started with a steep, but manageable, learning curve. When Generation II came around, the Pokédex had 100 new entries; an impressive addition, but still not overwhelming. Another 100+ were added in Generation III, and again in Generation IV. Fast-forward to two decades after the world met Pikachu, and there are over 800 Pokémon across seven generations.
Fans of the gaming franchise number in the hundreds of millions, and they prove their loyalty by crafting fan theories and creating Pokémon art. Yet even the most die-hard among them might not fully grasp the complete history of the Pokémon Universe, which is extensive (and not always logical).
Between all of the games, movies, and the TV show, the Pokémon Universe has slowly but surely filled out its entire history, from the creation of the universe to contemporary Pokémon training.
Just like the beginning of the real universe, the Pokémon Universe started with virtually nothing - just swirling molecules in chaos. Eventually, an egg manifested from all this nothingness. When hatched, the first being in the universe was born: a Pokémon named Arceus.
Arceus is known as "The Original One" and is considered the creator of the entire Pokémon World. Alone, Arceus began to create.
As the universe's singular entity, Arceus began to create. It made three fellow Pokémon: Dialga, Palkia, and Giratina, collectively known as the Creation Trio.
Dialga was given dominion over time, Palkia was given control of space, and the destructive Giratina was given rule over antimatter. When Giratina proved too destructive, Arceus was forced to send it to an alternate universe known as Distortion World. Arceus designed Distortion World to be a realm of punishment.
Meanwhile, Dialga and Palkia worked together to create the broader universe, including the Pokémon world. They then retreated to their own dimensions.
The Pokémon world began to create its own beings, the first legendary Pokémon of the planet. The pressure in the deep sea trenches formed Kyogre. Groudon developed deep inside the planet's core, forged from hardened magma and earth. Rayquaza was created by the minerals of the ozone layer.
Kyogre and Groudon began to form the topography of the Pokémon world, with Kyogre filling the seas and Groudon the land masses. Then, a new legendary Pokémon named Regigigas was born. The Titan Pokémon divided the continents with its power, thus creating the Pokémon world's different regions.
While the Legendary Pokémon were creating and dividing up the land, it is said Mew were abundant in the Pokémon world. Some have speculated Mew gave way to the hundreds of non-Legendary Pokémon we see in the series.
In Pokémon Silver, a professor says Mew's "DNA is said to contain the genetic codes of all Pokémon."