In 427 he was sent by his fellow-citizens at the head of an embassy to ask Athenian protection against the aggression of the Syracusans. He subsequently settled in Athens, and supported himself by the practice of oratory and by teaching rhetoric. He died at Larissa in Thessaly.

His chief claim to recognition consists in the fact that he transplanted rhetoric to Greece, and contributed to the diffusion of the Attic dialect as the language of literary prose. He was the author of a lost work On Nature or the Non-existent, the substance of which may be gathered from the writings of Sextus Empiricus, and also from the treatise (attributed to Aristotle; ascribed to Theophrastus) De Melisso, Xenophane, Gorgia. In this work he argued that

Nothing exists
Even if something exists, nothing can be known about it, and
Even if something could be known about it, knowledge about it can't be communicated to others

The authenticity of two rhetorical exercises, The Encomium of Helen and The Defence of Palamedes (edited with Antiphon by F. Blass in the Teubner series, 1881), which are attributed to him is disputed.

Gorgias is generally credited with having invented the philosophical doctrines of solipsism and nihilism in the statements above.

Link

Encomium on Helen (engl. translation) (http://www.missouri.edu/~engjnc/texts/gorgias_helen.html)

This article incorporates text from the public domain 1911 Encyclopædia Britannica.

G. S. Kirk, J. E. Raven, M. Schofield , The Presocratic Philosophers: A Critical History with a Selection of Texts , Cambridge University Press;