Casticus was a nobleman of the Sequani

Sequani

Sequani, in ancient geography, were a Gallic people who occupied the upper river basin of the Arar , the valley of the Doubs and the Jura Mountains, their territory corresponding to Franche-Comté and part of Burgundy.-Etymology:...

 of eastern Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

. His father, Catamantaloedes

Catamantaloedes

Catamantaloedes was the ruler of the Sequani of eastern Gaul in the early to mid-1st century BC, and was recognised as a "friend" by the Roman Senate. His son, Casticus, was later part of Orgetorix's conspiracy ca. 60 BC.-References:...

, had previously been the ruler of the tribe, and had been recognised as a "friend" by the Roman Senate

Roman Senate

The Senate of the Roman Republic was a political institution in the ancient Roman Republic, however, it was not an elected body, but one whose members were appointed by the consuls, and later by the censors. After a magistrate served his term in office, it usually was followed with automatic...

.

Ca. 60 BC, Casticus entered into a conspiracy with Orgetorix

Orgetorix

Orgetorix was a wealthy aristocrat among the Helvetii, a Celtic-speaking people residing in what is now Switzerland during the consulship of Julius Caesar of the Roman Republic. In 61 BC he convinced the Helvetians to attempt to migrate from Helvetian territory to south-western Gaul...

 of the Helvetii

Helvetii

The Helvetii were a Celtic tribe or tribal confederation occupying most of the Swiss plateau at the time of their contact with the Roman Republic in the 1st century BC...

 and Dumnorix

Dumnorix

Dumnorix was a chieftain of the Aedui, a Celtic tribe in Gaul in the 1st century B.C. He was strongly against alliance with the Romans, particularly Julius Caesar, who sparred with him on several occasions...

 of the Aedui

Aedui

Aedui, Haedui or Hedui , were a Gallic people of Gallia Lugdunensis, who inhabited the country between the Arar and Liger , in today's France. Their territory thus included the greater part of the modern departments of Saône-et-Loire, Côte-d'Or and Nièvre.-Geography:The country of the Aedui is...

to seize control of their respective tribes and between them rule Gaul. The conspiracy was discovered and put a stop to by the Helvetii.