"Seleucus" was a dynastic name in the Seleucid dynasty,[note 1][2][3] and it is the Macedonian variant of the Greek Ζάλευκος (zaleucus), meaning 'the shining white'.

[note 2][7][8] Antiochus VIII married the Ptolemaic Egyptian princess Tryphaena in c. 124 BC,[9] shortly after his ascension to the throne; Seleucus VI was the couple's eldest son.

[17] Following his father's death, Seleucus VI declared himself king and took the city of Seleucia on the Calycadnus in western Cilicia as his base,[18][19] while his brother Demetrius III took Damascus.

[note 6][21] As being the son of Antiochus VIII was the source of his legitimacy as king, Seleucus VI sought to emphasize his descent by depicting himself on the coinage with an exaggerated hawk-nose in the likeness of his father.

[32] Another iconographic element of Seleucus VI's coinage is the short vertical stubby horns above the temple area; the meaning of this motif has been debated among scholars.

[36] In Seleucia on the Calycadnus, Seleucus VI prepared for war against his uncle, whose forces probably occupied central Cilicia and confined his nephew to the western parts of the region.

[note 8][41] Seleucus VI gathered funds for his coming war from the cities of Cilicia, including Mopsuestia, which seems to have been taxed on several occasions.

[42] During his reign, it is estimated that Seleucus VI produced 1,200 talents of coins to support his war effort, enough to pay ten thousand soldiers for two years.

[note 9][47] This movement towards greater autonomy continued as the cities sought to emancipate themselves from the central power, adding the phrase "sacred and autonomous" to their coinage.

In Cilicia, as long as he reigned, autonomy was not granted; a change in the political status of Cilician cities was apparently not acceptable for Seleucus VI.

[57] Seleucus VI attempted to kill his cousin and rival but the plot failed,[58] and Antiochus X married Cleopatra Selene to enhance his position.

[60] Described by the 2nd-century historian Appian as "violent and extremely tyrannical",[61] Seleucus VI took shelter in Mopsuestia,[62] and attempted to tax the residents again, which led to his death during riots.

Given the fragmentary nature of ancient sources regarding the late Seleucid period, the statement of Lucullus leaves open the existence of a wife or daughter of Seleucus VI.

[68] Ancient traditions preserve three accounts regarding Seleucus VI's death: the oldest, by Josephus, has a mob burning the king and his courtiers in the royal palace.