The emigrants urged him to strike: the position of Sertorius in Spain, as to which Mithradates despatched envoys under convenient pretexts to the headquarters of Pompeius to obtain information, and which was about this very time really imposing, opened up to the king the prospect of fighting not, as in the first Roman war, against both the Roman parties, but in concert with the one against the other.

A more favourable moment could hardly be hoped for, and after all it was always better to declare war than to let it be declared against him.
In 679 Nicomedes III Philopator king of Bithynia, died, and as the last of his race--for a son borne by Nysa was, or was said to be, illegitimate--left his kingdom by testament to the Romans, who delayed not to take possession of this region bordering on the Roman province and long ago filled with Roman officials and merchants.

At the same time Cyrene, which had been already bequeathed to the Romans in 658,( 10) was at length constituted a province, and a Roman governor was sent thither (679).

These measures, in connection with the attacks carried out about the same time against the pirates on the south coast of Asia Minor, must have excited apprehensions in the king; the annexation of Bithynia in particular made the Romans immediate neighbours of the Pontic kingdom; and this, it may be presumed, turned the scale.

The king took the decisive step and declared war against the Romans in the winter of 679-680.
Preparations of Mithradates Gladly would Mithradates have avoided undertaking so arduous a work singlehanded.