The eastern part was given to Adherbal and the larger western part was given to Jugurtha after he bribed the commissioner. Jugurtha eventually had Adherbal torchered to death he became King. This form of corruption occurred all throughout the Roman empire. Several wars were to follow this war including the mithridatic wars and the slave wars. Eventually Julius Caesar came into power and after him Octavian. The corruption continued through the line of emperors there was bribery and assassinations trying to gain political power. This along with wars and expansion lead to the western empires fall.
The tribes that were involved with the fall of the Roman empire are the Goths, Visigoths and Vandals. There were others such as: Frank, Angles, Alamanni, and Saxons. These tribes basically wrecked havoc everywhere because they were against the Roman empire, they are rebels to put in simple terms. They would raid towns and create many uproars trying to bring the empire