There was no central sanctuary, no Levitical priesthood, no Mosaic Law.

The "duke" consequently had no rival; the history of Edom knows nothing of judges or high-priests.
The law of evolution, however, which governed other Semitic communities prevailed also in Edom.

The dukes had to give place to a king.

The tribes were united under a single leader, and the loosely federated clans became a kingdom.

As in Israel, so too in Edom the kingdom was elective.