How about this...
When Erek Nohan arrived in the area, he was accompanied by his grandmother Lady Kelvin, a sweet elderly lady with a habit of chiding him for his use of swear words but a powerful sorceress in her own right.
[skip to splitting up the region between Mor and Kulpin]
Mor founded Mor's End, but left the day-to-day running of the city in the surprisingly capable hands of Lady Kelvin. Erek Nohan founded the library in Mor's End, searching for knowledge about it's ancient past. Nobody knows for sure what became of him, but some say his ghost still roams the stacks. Others say he descended in the Warren and met a gristly fate there.
The first Lady Kelvin died several years later under mysterious circumstances. Around the same time the now aging Mor acquired a new mistress, who soon proved to be a capable admistrator. Before his death, Mor appointed her as head of the city, carrying the "Lady Kelvin" title which people had come to associate with the position. Ever since then, the rulership of the city, and the title, have been passed on from mother to daughter. All of the Lady Kelvin's have had raven-black hair, and the same striking green eyes as the very first Lady Kelvin - Erek's grandmother.
There are rumors that the ancient sorceress found a way to cheat death, moving her spirit from mother to daughter, or just rejuvenating her body every generation. Of course, those are only rumors... or are they?