Timeline

This timeline is very preliminary and not all the dates or even the order are to be considered even close to concrete.

Prehistory
Many different magical realms existing in many different locations begin to slowly create and develop portals to other worlds. They all, for some reason, end up opening in the Sol Star System. Earth and the other planets close to Earth become hubs of activity and interaction between many magical realms.

Silver Millennium
Over time, an alliance is formed with Earth's moon as the epicenter thanks to the benevolant and wise guidance of Queen Serenity. Considered by many historians to be the Golden Age. Many of the greatest wars and love stories got their start during this time period.

Downfall of the Silver Millennium
The last of the magical wars creates an all out battle between the forces of Order and Chaos breaks many former alliances and forges new ones as the planes are forced to pick sides and fight for their very survival. Many of the most powerful magic users on both sides are either defeated and slain or, if too powerful, bound and banished to the deepest recesses of the Earth. The survivors agree that to prevent such a thing from happening in the future, the portals to the Sol System must be sealed and once again the planes isolated. Many of the survivors return to their home, several remain on Earth as stewards to the fallen and bound. Queen Serenity uses the last of her power to seal the Age of Magic from collective memory thus leaving a small handful of mages upon Earth with the knowledge of what has transpired and, of those, even fewer with the power to create new portals.

The Dark Ages
Over time, the knowledge, technology and power of magic that saw it's height during the Silver Millinium wanes. Across all planes, only a small handful of individuals within each plane still retain the knowledge to open portals to other realms but such knowledge are jealously guarded secrets taught only to successors and then only if they are considered 'worthy'. The Age of Magic has been all but forgotten. Every so often, the barrier between planes weaken and individuals are able to slip from one side of the barrier to the other, this explaining the unique phenomenon of 'magicless' Earthlings falling into magical planes and beings and creatures of other realms appearing on Earth.

Magic did not truly disappeared from Earth however. With the presence of so many prisoners locked beneath the Earth's surface, the guardians raised families, created cabals and clans to pass on their heritage. Of those bound beneath the surface, a few managed to retain consciousness and enough power to create or seduce minions and followers who's purpose would be to release their masters from their prison. To hone their skills and ensure the protection of Earth, the children of these clans were sent to schools like Merdiana Magic Academy, Mahora Academy and Hoggwart's. In the core families, the ability remained strong and it is from one of these families was born one of the most powerful magicians of East and Western magic, Clow Reed. He and a powerful Japanese magic user known only as Yuuko explore the magic world, establishing communication with and discovering entities of other planes long forgotten by even the Guardians themselves. While the exact nature of his relationship with Yuuko remains unknown, the result of it created such a wave through the magical community that it can still be felt in the Modern Times.

Because of his Wish and the power in him, the very fabric of reality began to warp in attempt to accomodate. Barriers between planes began to weaken and many of those bound by ancient magics began to awaken or had their chains weakened. Magic was re-entering the world. Slowly all over the world, individuals with latent magical powers began to awaken while more demonic minions appeared.

Magiquake!!
Fifty years ago, a massive tremor echoes through the Magical World causing already delicate barriers to break even further and more portals to open. Space and time bend and it catches the attention of the Time-Space Administration Bureau. Earth is found to be at the epicenter of all this but the situation quickly dies down. The TSAB leaves a station upon the moon to keep an eye on the situation but otherwise ignore the unadministered planet.

Modern Era
The time has come. A massive surge in magic has flooded the Earth. Those once bound are free or close to free, prophecies are coming true, seemingly ordinary individuals find themselves with new and awesome powers, the barriers have fallen and the planes are once again open. Those who seek and crave power have come to Earth to try and harness all the free flowing magic and others have risen to protect the Earth from these new and unwelcome invaders.