Demetrius I (r. 162 BC - 150 BC), surnamed Soter,
was a ruler of the Hellenistic Seleucid Empire. He
had been sent to Rome as a hostage during the reign
of his father, Seleucus IV Philopator. After his
father's death in 175 BC, Antiochus IV Epiphanes
took advantage of Demetrius' captivity to seize the
throne. Demetrius escaped from confinement and
established himself on the Syrian throne (162 BC)
after overthrowing and murdering King Antiochus V
Eupator, his cousin.
Demetrius acquired his surname of Soter, or
Saviour, from the Babylonians, whom he delivered
from the tyranny of the Median satrap, Timarchus.
Timarchus, who had distinguished himself by
defending Media against the emergent Parthians,
seems to have treated Demetrius' accession as an
excuse to declare himself an independent king and
extend his realm into Babylonia. His forces were
however not enough for the legal Seleucid king:
Demetrius defeated and killed Timarchus in 160 BCE,
and dethroned Ariarathes, king of Capadoccia. The
Seleucid empire was temporarily united again.
Demetrius is famous in Jewish history for his
victory over the Maccabees.
Demetrius' downfall is attributed to Heracleides,
a surviving brother of the defeated rebel Timarchus,
who championed the cause of Alexander Balas, a boy
he claimed was a natural son of Antiochus IV
Epiphanes. Heracleides convinced the Roman senate to
support the young pretender against Demetrius, who
was defeated and killed in 150 BC. Thus the family
of Timarchus contributed in no little way to the
disintegration of the Seleucid empire.
This entry incorporates material from the 1911
Antiochus V Eupator