Map showing the growth of Bosporan Kingdom under the Spartocids dynasty.
Own work. Source:

Background map: File:Ancient Greek Colonies of N Black Sea-fr.svg by Sémhur under licence FAL or CC-BY-SA 3.0
Data : MBNPAM126B.jpg in Supplementum Epigraphicum Graecum Neapolis
Sémhur (talk)