Sage Guru was born from the Crystal Heart, when the world races were not getting along, and the first world super powers, (the Crystal Empire and the Klip Klop Kingdom,) were obsessed with social perfectionism. The son of the creator, Empress Lauren Fausticorn, the first alicorn himself at first preferred not to fight at all, until along came Grogar, and accused him of being an oddity of nature. Sage tried to reason with him, but he made so little sense to Grogar, that he deeply cut his face, giving him a scar, and throwing him in prison. The scar remained a permanent reminder of why even pacifists should fight back in defense.

In time, his half-sister, the first high monarch alicorn Queen Parabola, as well as his cousin, the all-powerful magic prodigy Starswirl the Bearded, were also thrown in Equestrian prison. However, Sage, his half-sister, and his cousin were all given a plea deal. The more evil Majesty IV had betrayed the tyrannical Grogar for her own, personal gain, and out of desperation, Grogar claimed that if they defeated her, and put an end to her rule, within eight months, he would give them all a full pardon.
Among the way, he met Tia Daybreak (Celestia), Luna Moon, Stygian, Tree Fairy, Dusk Glimmer, and Carefree, who became his students, and his mother anointed him the first sages of wonders (sometimes called sages of wisdom.) It was believed that he and his cousin co-wrote a series of spells, some of which were taught to their students, and were meant to be used against Queen Majesty IV.
Unfortunately upon arrival, they were captured, and Majesty used one of her killing the unkillable spells, “the Cheap Slap”, to swell up Queen Parabola’s head until it exploded, killing her. She also corrupted Tia, turning her into a ruthless warrior. Thankfully, Sage, his cousin, and their students, all escaped, managed to get Tia back on their side, and sealed Majesty’s physical form into a Manchineel tree. As a reward, Sage was blessed by She, the Empress of all herself, with her power, making him the new high monarch alicorn, King Sage Guru. Additionally, all the students became alicorn princes and princesses, Tia Daybreaker was renamed Celestia, and as promised, Grogar pardon them.

For thousands of years, he, and the alicorn students, had kept harmony throughout the land, including the birth of the Elements of Harmony, the defeat of Grogar, and the peace brought to the Crystal Empire. It all came to an end one day, tragically. After word got out that one of his former fans lead a revolution, becoming King Sombra, and that he mistreated ponies that were not different, the alicorn seven and Starswirl snuck into its capital, bringing their most trusted ally at that time. One of whom was Radiant Hope, who tried to reason with Sombra one final time, and showed them where they were hiding. Sombra threw some restraints onto sage, apologized that he believed had no choice but to charge him with Impersonating royal blood, attempted overthrow of the government, and witchcraft.
The five restraints each let him experience the fear, hatred, and envy he had been holding back all these years. So he would be too overwhelmed to fight back, as Sombra attached him to a T-shaped poll, on top of a cabin firewood pile. Sage’s last words were, “Someone once asked me, I remember not whom, if thou should judge based on race or actions. I replied neither, thou shall judge based on character. I can tell that deep down you wish not to do this, for you show remorse. I hope one day you realize this, and Empress will have mercy on your soul.” King Sombra paused, then lit a blue fire, activating another one Majesty IV’s killing the unkillable spells, “ The Blue Ritual Execution.”

After Sage’s death, the seventh element split into five pieces, the alicorn students banished the capital of the Crystal Empire into the abyss, and things got so out of hand between Celestia and Tree Fairy that Celestia banished half of the alicorns from Equestria forever. Starswirl tried to convince Celestia otherwise, but since Sage never chose a successor, and she was the most powerful of the alicorn students, she saw herself as such. Celestia erased all traces of Sage Guru from the records, seeing it as a reminder of the alicorns that were banished. However, legends outside of Equestria say that his soul is in a realm, on the top of the Echo Mountains, in the land of Bermelia, waiting for the true successor, for the Empress Lauren Fausticorn has been said to be dead, forcing the alicorns to take her place.