How did the Ten Generals in Ancient Athens come into being?

Under the reform of Cleisthenes, four generals appointed by the four major tribes in Athens were dissolved with the formation of the new ten tribes. Instead, ten generals were appointed every year, one for each tribe. Ten will be a few officials of the city-state, not appointed by lot, but elected and can be re-elected many times. Every year at the tribal citizens' meeting, citizens will choose the best military talents in the tribe as the nominees of tribal generals. The nomination of the general will be confirmed and passed at the city-state assembly. Generally speaking, the person nominated by the tribe will be decided by the citizens' assembly.

The general's main task is to command the naval fleet and the Athenian army. At first, the general only commanded the troops of his tribe. However, with the change of the battlefield environment, this situation of being only responsible for one's own tribe seems out of place, especially with the transformation of Athens from a city-state to an empire, generals need greater autonomy to perform their duties on overseas battlefields. However, even if the general has great power, that is, as a minority official of the city-state, even if the general can be re-elected, in any case, the general must obey the decision of the parliament. According to Aristotle's Athens political system, one of the generals was responsible for defending the land territory of the city-state, another compiled a list of captains of warships, and two generals were responsible for defending the port of Piraeus.