Question: Gaius Cassius Longinus, was a Roman senator, a leading instigator of the plot to kill Julius Caesar, and the brother in-law of Marcus Junius Brutus, he commanded troops with Brutus during the Battle of Philippi against the combined forces of which Roman politician and general who played a critical role in the transformation of the Roman Republic from an oligarchy into the autocratic Roman Empire?
Sentence (from "Ptolemy XIV of Egypt"): It has been assumed but remains uncertain that Cleopatra poisoned her co-ruler, with aconite, to replace him with his nephew Ptolemy XV Caesarion, her son by Caesar who was proclaimed co-ruler on September 2, 44 BC and whom his mother intended to support as successor of his father.
Relevant evidence: No