In Europe, witches and wizards of the 15th (15th) century hid by the shadows of the Courts of the Inquisition who chased, captured and burned all who were accused of practicing black magic.
Jay Lohrein was a great wizard at the time continued to run from the inquisitors, until one day he was found.
During a long time of persecution Jay Lohrein finds one of his magic books hidden inside from an old hut and uses it to make a spell, this spell generated the creation of a new universe generated entirely from scratch, the mage does not lost time and soon entered the new universe.
What he didn't know is that his magic would attract more people from other times to the same universe generated, thus forming a multiverse.