Tobias was born in 1859 mute and deaf until his mutant powers activated at nineteen years old allowing him to communicate telepathically. Once he was thirty he started traveling around the world looking for other mutants such as himself. Around the age of 50 he had formed a group with mutants such as himself and together they were able to assist in ending the first World War. Within 10 years time Tobias was the only one left of the original group, the others succumbing to old age.
Once he was the sole survior of his group Tobias started to place himself in suspended animation emerging once every decade to record the progress of the world and to seek new mutants to join him in his cause. This new group became the Promise and Tobias was their leader. He believes a war between mutants and humans is inevitable and he wants himself and his group to be there during the aftermath to help lead and guide the mutants who he feels will inevitably win while also rebuilding for a better future.
Tobias recruited up Craig Farnsworth, Simon Lestron, and Gene Bitner soon after they were freed by the F.B.I.'s Jimmy Woo against the Yellow Claw and his hypnotism which he was using to force them into working for him.
Lucy Robinson was recruited when she was but a simple housewife with martial problems and a family.
Ernest Scope and Gracie Smith's recruitment period is unknown.
X-Men: The Hidden Years
When the X-Men were still fairly new in the world Tobias and the rest of the Promise decided to try and take the newest members of the X-Men, Lorna Dane and Alex Summers unwillingly into their group. Tad, Simon, and Gene scouted out the X-Men and were the ones that passed on the information to Tobias.
After they had already taken Lorna the X-Men pursued them to save her however the Promise was ready for them. Craig was able to use his power called dreamcasting to pit the X-Men against each other making them each appear as monstrous looking creatures to one another which caused them to take each other out. Havok was the only one remaining until Gracie kissed him and used some sort of energy drain mutant power to take him out as well. Since Lorna and Alex had the least connection to Charles Xavier and his beliefs and perceptions of mutants Tobias felt they'd come around to their cause more easily. Lucy Robinson talked Tobias into also taking Warren Worthington III as well. Through the use of "teaching circuits" Tobias had hoped the new recruits would wake up with an understanding of his cause and join willingly after that.
However Lucy was able to rig her and Angel's suspended animation cylinder causing them to awaken in a much shorter time. She wanted out of the Promise because she believed Tobias has become obsessed with his dream and that he doesn't care who's lives he ruins in obtaining his goal. Lucy herself abandoned her family for Tobias's crusade to save the world.
Eventually Lucy was able to wake up Lorna and the rest of the Promise except for Tobias, who suspiciously couldn't wake up even though his vitals were normal moments prior. It's hinted at by Lucy herself that she had something to do with it and that Tobias is dead. The remaining members of Promise decided it best to remain awake and help mutants now before a war that may or may not even happen.
Craig and Gracie decided to adopt Simon in a way since he was still in the body of a kid they thought it better for him to stick with them.