Cornelius Nepos
Some episodes of Epaminondas's life can be found in Plutarch's "Lives" of Pelopidas and Agesilaus II, who were contemporaries. There is also a surviving (and possibly abridged) biography of Epaminondas by the Roman author Cornelius Nepos from the first century BC which, in the absence of Plutarch's, becomes a major source for Epaminondas's life.