Where does “regățean” come from?

regățean (Romanian) comes from Romanian regat, from Romanian rege, from French roi, from Middle French roy, from Old French roi, from Latin rēx, from Proto-Italic rēks, from Proto-Indo-European h₃rḗǵs — to straighten, to right oneself; right; just.

regățean (Romanian): person from the Old Kingdom of Romania (Wallachia and Moldavia)