In Which way was the governing process of Sparta most similar to that of Athens

Rivals of Ancient Greece (Athens and Sparta) had some similarities in the governing system of the states. They both had an "assembly" whose members were elected by the citizens of the states. On the one hand, Sparta was ruled by two kings (elected by people) till they died or overpowered by the citizens, whereas the rule of Athens was in the hands of Archons (the elected members).