What event 'triggers' your first followers opening up?

[OGXanos]

I had read it was just your first earned artifact point (not the free one) but that doesn't seem to be it. Supposedly 93 opens the first extra few as well. Reasoning here is I want to get my alts setup for the app use. Figure I can get 1-2 levels setup by light resource collection 1 day a week. Any help here is appreciated.

[wongeun]

Turning level 101 will trigger a quest when you enter Dalaran that takes you to your order hall (think you can go directly there, as well). Then you'll get your first followers, followed by the small tutorial for missions.
Level 103 is required for your next two followers