Diodotus Tryphon in Wikipedia
Diodotus Tryphon (Greek: Διόδοτος Τρύφων) was king of the Hellenistic Seleucid kingdom. As a general of the army, he promoted the claims of Antiochus VI Dionysus, the infant son of Alexander Balas, in Antioch after Alexander's death, but then in 142 deposed the child and himself seized power in Coele-Syria where Demetrius II Nicator was unpopular for his oppressive treatment of the Jews.
The internal situation in the Seleucid domains was so convoluted, and Diodotus was so eager to gain allies, that in 143 BC Hasmonean rule was reinstated in Judea in exchange for aid. True to their word, several Jewish armies marched against Diodotus' rival Demetrius and opposing cities. However, the Jewish forces under the High Priest Jonathan behaved too boldly, leading to his capture and murder by ruse when Diodotus marched into Judea. Despite his preparations and intentions to cow the Jews, Diodotus was entirely unsuccessful, and left the region under the rule of Jonathan's brother Simon, with little gain beyond a minor tribute of 100 talents. Finally, in 138 Diodotus was attacked and defeated in Antioch by Antiochus VII of Side. Diodotus committed suicide after his defeat.
In 138 BC, Diodotus claimed that his charge had contracted an illness and supposedly required surgery, during which he died - presumably disguising his murder at his supposed benefactor's bequest.