This is a bust of Zeno of Kition (also known by its Latin name Citium), he is one of the most notable Greek philosophers of the Hellensitic period.
In the 3rd Century BC he founded Stoicism, the set of doctrines that are midway between the obsession with duty and the cynic’s rejection of society. If you’ve heard the phrase “man conquers the world by conquering himself” then you have heard one of Zeno’s quotes.
Like the cynics, Zeno recognised a simple good, rejecting all desires for wealth, power and fame and living with the bare necessities required to exist. But he also recognised the Stoics acceptance of Fate, that whatever happens, happens, and there is no point in complaining about it. He lectured his students on the value of apatheia – the absence of passion, arguing that only by controlling one’s emotions and physical desires could one develop wisdom and apply it.
Stoicism dominated the Roman and Hellenistic periods and even went on to influence Christianity. None of Zeno’s own works have survived to modern era, all that is known about him, is known from his followers and critics.