The lanes were a powerful force of nature that was bestowed onto the multiverse. they were the origin of connection and power amongst the human within each universe. Some humans who could sense them, and their bodies would later adopt and would be able to draw power that would go against the laws of nature.
These people would come to be known as mages. They were warriors, politicians, and beings who were worshiped as gods in many universes. No one knew the original origin of the lanes. The Eldriym theory went by the idea that the lanes were a residue of the creation of the lords of balance.
But they were wrong because they made that up to console themselves. It was human nature.
However, a group of Eldriym Mages and Warlocks called the Magisterium set themselves on a journey to discover what was the actual origin of magic and the lanes. This was before the discovery of the multiverse and other realms.