Celes II is an inhabited planet located near the Romulan Star Empire, known as a rich source of dilithium.
In 2379, the Romulan Senate debated on a pending trade agreement with Celes II, with concern that if they hesitated they would lose this important source of dilithium. Since the agreement was in the best interests of the Empire, it was recommended that the Empire dispatch a diplomatic mission to the planet to open negotiations. (Star Trek Nemesis)