Gauls
In 58 BC Julius Caesar launched the Gallic Wars and had conquered the whole of Gaul by 51 BC. He noted that the Gauls (Celtae) were one of the three primary peoples in the area, along with the Aquitanians and the Belgae. Caesar's motivation for the invasion seems to have been his need for gold to pay off his debts and for a successful military expedition to boost his political career. The people of Gaul could provide him with both. So much gold was looted from Gaul that after the war the price of gold fell by as much as 20%. While they were militarily just as brave as the Romans, the internal division between the Gallic tribes guaranteed an easy victory for Caesar, and Vercingetorix's attempt to unite the Gauls against Roman invasion came too late. After the annexation of Gaul a mixed Gallo-Roman culture began to emerge.
Segni (tribe)
The Segni (sometimes Segui) were a tribe living in Belgic Gaul when Julius Caesar's Roman forces entered the area in 57 BCE. They are known from his account of the "Gallic War". They were one of a group of tribes listed by his local informants as the "Germani" of Belgian Gaul, along with the Eburones, Condrusi, Paemani (or Caemani), and Caeroesi (or Caeraesi). The Segni do not appear in the first listing of the Germani, which was a listing of Germani sending men to fight Caesar. But they appear in a later mention, after the defeat of the Eburones: The Segui and Condrusi, of the nation and number of the Germans ["Germani"], and who are between the Eburones and the Treviri, sent ambassadors to Caesar to entreat that he would not regard them in the number of his enemies, nor consider that the cause of all the Germans on this side the Rhine was one and the same; that they had formed no plans of war, and had sent no auxiliaries to Ambiorix. Caesar, having ascertained this fact by an examination of his prisoners, commanded that if any of the Eburones in their flight had repaired to them, they should be sent back to him; he assures them that if they did that, he will not injure their territories.