In 49 BC, a civil war broke out within the Roman Republic between Julius Caesar and the senate, which was led by Pompey the Great.
The Mauretanians seemed to have picked the right side as the war swung in the favour of Julius Caesar following the Battle of Pharsalus and Pompey the Great’s murder in Egypt.
The surprised Pompeians, possibly outnumbered by the garrison whose size is unknown, were quickly broken and fled back to their ships.
[3][pages needed] This attack spurred the Mauretanians into action, and with the help of the mercenary Publius Sittius they invaded and seized much of Numidia.
Following Caesar’s invasion of Africa and victory at the Battle of Thapsus, many Pompeians fled westward, only to find their escape blocked by the Mauretanians, with many captured and killed and others committing suicide.