In the Ancient Greek diplomacy,  they preferred oral messages to written notes; therefore, there is not a large archive of diplomatic correspondence of ancient Greece.

There were three kinds of representatives:

• angelos: a messenger used for brief and specific missions

• keryx: a herald

• proxenos: a resident consul but the proxenos were citizens of the city in which they resided, not of the city-state that employed them. If a resident representative was needed in another state, then a resident was given the title of proxenos by the state which he represented. In other words, the proxenos looked after the interests of a foreign state while residing in the state of which he was a citizen.

Envoys were selected from among the prominent members of the state by the city assembly and they were not necessarily qualified persons. They were rather chosen for their political stance and for their association with the state which they were negotiating with. Representatives were first expected to show their oratorical abilities. The number of members in a mission ranged from three to ten men, and they were given brief instructions such as; ratifying treaties by oral oath, inquiring about terms for peace, and solving a dispute in the interest of the community.