Sparta was the most powerful oligarchy in ancient Greece. Citizens made up only about 10 per cent of the population. Most people were serfs who farmed the land. Two kings, who inherited their thrones, headed the army. Sparta was governed by 5 officials, called ephors, and the gerousia, a council made up of 28 elders and the kings. Citizens elected ephors to one-year terms and members of the gerousia to life terms. Sparta had a citizen assembly. But citizens could not propose issues for debate in the assembly.