Unlike Plato's Academy or Zeno's Stoa, Cynicism is not attested as a formally organized school with one identifiable founder, founding place or fixed set of doctrines; ancient sources give rival, uncertain traditions crediting Antisthenes, Diogenes of Sinope, or both, and it is not even certain the two men ever met.
What would resolve this A firmer body of contemporary ancient testimony fixing a specific founding teacher, place and date, which the surviving sources do not provide and later doxography likely cannot supply.
OpenHistory of ancient philosophyCynicism (Encyclopedia of Philosophy via Encyclopedia.com)