Who all knows about Socrates?

Socrates (469-399), despite his foundational place in the history of ideas, actually wrote nothing. Most of our knowledge of him comes from the works (in the form of dialogues) of Plato (427-347), and since Plato had other concerns in mind than simple historical accuracy it is usually impossible to determine how much of his thinking actually derives from Socrates. Although Socrates is the central figure of Plato's dialogues, little is actually known about him. He left no writings, and what is known is derived largely from Plato and Xenophon.