Nicomēdes I., king of Bithynia, was the eldest son of
Zipoetes, whom he succeeded, B.C. 278. With the aid of the Gauls, whom he invited into Asia,
he defeated and put to death his brother Zipoetes, who had for some time held the independent
sovereignty of a considerable part of Bithynia. The rest of his reign appears to have been
undisturbed, and under his sway Bithynia rose to a high degree of power and prosperity. He
founded the city of Nicomedia, which he made the capital of his kingdom. The length of his
reign is uncertain, but he probably died about 250. He was succeeded by his son Zielas.
Nicomēdes II., surnamed Epiphănes
, king of Bithynia, reigned B.C. 149-91. He was the
son and successor of Prusias II., and fourth in descent from the preceding. He was brought up
at Rome, where he succeeded in gaining the favour of the Senate. Prusias, in consequence,
became jealous of his son, and sent secret instructions for his assassination. The plot was
revealed to Nicomedes, who thereupon returned to Asia, and declared open war against his
father. Prusias was deserted by his subjects, and was put to death by order of his son, B.C.
149. Of the long and tranquil reign of Nicomedes, few events have been transmitted to us. He
courted the friendship of the Romans, whom he assisted in the war against Aristonicus, 131.
He subsequently obtained possession of Paphlagonia, and attempted to gain Cappadocia by
marrying Laodicé, the widow of Ariarathes VI. He was, however, expelled from
Cappadocia by Mithridates; and he was also compelled by the Romans to abandon Paphlagonia,
when they deprived Mithridates of Cappadocia.
Nicomēdes III., surnamed Philopator, king of Bithynia (B.C. 91-74), son and successor of Nicomedes II.
Immediately after his accession, he was expelled by Mithridates, who set up against him his
brother Socrates; but he was restored by the Romans in the following year (B.C. 90). At the
instigation of the Romans, Nicomedes now proceeded to attack the dominions of Mithridates,
who expelled him a second time from his kingdom (B.C. 88). This was the immediate occasion of
the First Mithridatic War, at the conclusion of which (B.C. 84) Nicomedes was again
reinstated in his kingdom. He reigned nearly ten years after this second restoration. He died
at the beginning of B.C. 74, and, having no children, by his will bequeathed his kingdom to
the Roman people.
A geometrician famous for the invention of the “conchoid curve,” much
used by the ancients in solid geometry. See Ball's Short History of
, p. 78 (London, 1888)