Eight centuries ago, the already-arid drell homeworld, Rakhana, began its swift descent into lifelessness due to disastrous industrial expansion. Because their population was bursting at 11 billion and they did not possess interstellar flight capability, the drell would have been doomed without the intervention of the hanar.
Following first contact, the hanar spent ten years transporting 375,000 willing drell to their own homeworld, Kahje. The remaining billions perished in the dying world, warring against each other for diminishing sources of water and food, today, a few thousand survive on Rakhana in clusters never exceeding a few hundred. Now a cemetary world, Rakhana's population can double during Pilgrimage season.
Drell have been part of the galactic community for almost two centuries. Most reside on Kahje, content to coexist with the hanar. Those who leave Kahje tend to be adventurers. Gifted by the hanar with acute perception of interspecies body language, solitary drell travelers often seek out new species elsewhere, adopting that species' culture and rarely returning to Kahje. Such drell number in the thousands and are scattered across the galaxy, tending towards quiet integrated lives.
On Kahje, the hanar afforded the drell every opportunity to thrive. While outsiders and even some hanar regard the drell as junior partners, if not actual servants, drell have integrated themselves into every level of hanar society as respected productive citizens.