Question: In pre-Roman Gaul the Belgic tribe of the Veliocasses or Velocasses controlled a large area in the lower Seine valley, which retains a trace of their name, as the Vexin, in 52 they raised 3000 men to support which son of Celtillus the Avernian, leader of the Gallic tribes?
Sentence (from "Vercingetorix"): He immediately established an alliance with other Gallic tribes, took command and combined all forces, and led them in the Celts' most significant revolt against Roman power.
Relevant evidence: No