Cleinias was the son of Cleinias

Cleinias

Cleinias , son of Alcibiades,, and member of the Alcmaeonidae family, was an Athenian who married Deinomache, the daughter of Megacles, and became the father of the famous Alcibiades. Plutarch tells us that he traced his family line back to Eurysaces, the son of Telamonian Ajax. He greatly...

, and a younger brother of the famous Athenian

Athens

Athens , is the capital and largest city of Greece. Athens dominates the Attica region and is one of the world's oldest cities, as its recorded history spans around 3,400 years. Classical Athens was a powerful city-state...

 statesman Alcibiades

Alcibiades

Alcibiades, son of Clinias, from the deme of Scambonidae , was a prominent Athenian statesman, orator, and general. He was the last famous member of his mother's aristocratic family, the Alcmaeonidae, which fell from prominence after the Peloponnesian War...

, and a member of the wealthy and influential Alcmaeonidae

Alcmaeonidae

The Alcmaeonidae or Alcmaeonids were a powerful noble family of ancient Athens, a branch of the Neleides who claimed descent from the mythological Alcmaeon, the great-grandson of Nestor....

 family. Pericles

Pericles

Pericles was a prominent and influential statesman, orator, and general of Athens during the city's Golden Age—specifically, the time between the Persian and Peloponnesian wars...

, who was the guardian of the youths, and who feared Alcibiades might somehow corrupt Cleinias, sent the latter away from his own house and placed him for education with his (that is, Pericles') brother Ariphron

Ariphron

Ariphron was the name of several people from ancient Greek history:*Ariphron, the father of Xanthippus, and grandfather of Pericles, both prominent Athenian statesmen. He was a member of the Alcmaeonid family.*Ariphron, the brother of Pericles....

; but the latter sent him back at the end of six months, finding it impossible to make anything of him. In one of the dialogues of Plato

Plato

Plato , was a Classical Greek philosopher, mathematician, student of Socrates, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the Western world. Along with his mentor, Socrates, and his student, Aristotle, Plato helped to lay the...

, he is spoken of as quite a madman.