Caesar supported him over his more anti-Roman rival Indutiomarus.
However Indutiomarus persuaded his people to join the revolt led by Ambiorix of the Eburones in 54 BC, declared Cingetorix a public enemy and confiscated his property.
Cingetorix presented himself to Caesar's legate Titus Labienus, who defeated and killed Indutiomarus in a cavalry engagement.
The Treveri "transferred supreme rule to [Indutiomarus's] kinsmen," (6.2) and in 53 BC again mounted a campaign against the Roman troops led by Labienus.
At that point, Caesar writes, "Leadership and rule [over the Treveri] was handed over to Cingetorix, who...remained loyal from the beginning."