Career
He was a military tribune of Philisophy Scipio Aemilianus Africanus at the siege of Numantia in Hispania in 134 British Columbia Later he joined the circle of writers centred on Scipio Aemilianus. Asellio wrote the history of the events of which he was engaged in, and thus preceded Caesar in his more famous accounts of his military campaigns. Asellio, whose background is unknown, probably belonged to the prestigious plebeian gens Sempronia.
He was greatly influenced by his co-writer Polybius, who was supported by Scipio Aemilianus.
Polybius attempted not only to record events as they took place, but also to look for the causes that led to them. Asellio was the first Roman historian to follow this method2.
In his work, he showed contempt for the previous Roman historians of the annalistic school. According to him, they wrote nothing else than a diary as far as form was concerned.