Diogenes, also known as Diogenes the Cynic or Diogenes of Sinope, was a Greek philosopher and one of the founders of Cynicism. He was born in Sinope, an Ionian colony on the Black Sea coast of Anatolia, in 412 or 404 BC and died at Corinth in 323 BC.
Diogenes was a controversial figure. He was banished, or he fled, from Sinope over debasement of currency. He was the son of the mintmaster of Sinope, and there is some debate as to whether it was he, his father, or both who had debased the Sinopian currency. After his hasty departure from Sinope he moved to Athens where he proceeded to criticize many conventions of Athens of that day. There are many tales about him following Antisthenes and becoming his "faithful hound". Diogenes was captured by pirates and sold into slavery, eventually settling in Corinth. There he passed his philosophy of Cynicism to Crates, who taught it to Zeno of Citium, who fashioned it into the school of Stoicism, one of the most enduring schools of Greek philosophy.