The movement lasted intermittently for some 800 years or more, flourishing mainly in its first two centuries and again under the early Roman Empire (first two centuries AD).
The Cynics were akin to and in some ways forerunners of the Stoics, but they confined themselves to ethics and never gained the respectability of the Stoics.
Like the Stoics they advocated self-sufficiency, and the avoidance of emotional entanglements and slavery to desire, but unlike stoicism they rejected social conventions and constraints as unnatural. The name 'Cynics' means 'doggy ones', perhaps because of their uninhibited habits (though other etymologies have been suggested).
D R Dudley, A History of Cynicism (1937)