Short answers, pulled from the story.
Gnaeus Pompeius Magnus (born around 75 BC, died the 12th of April 45 BC) was the elder son of Pompey the Great and his third wife, Mucia Tertia. He was a Roman politician and general who led resistance against Julius Caesar during the late Republic's civil wars alongside his brother Sextus Pompey.
Gnaeus Pompeius Magnus was cornered and killed by Lucius Caesennius Lento in the weeks following the Battle of Munda on the 17th of March 45 BC. He died on the 12th of April 45 BC, at approximately thirty years old.
At the Battle of Munda on the 17th of March 45 BC, the Pompeian forces led by Gnaeus and Sextus Pompey, along with Titus Labienus, were defeated by Julius Caesar after a cavalry charge turned the battle. An estimated 30,000 men on the Pompeian side were killed, including Titus Labienus, though both brothers escaped.
Gnaeus Pompeius Magnus married Claudia Pulcra, daughter of Appius Claudius Pulcher and sister of the first wife of Marcus Junius Brutus. Claudia survived her husband; they had no children.
Sextus Pompey was the younger brother of Gnaeus Pompeius Magnus, both sons of Pompey the Great. They fought together through the African and Hispanian campaigns against Caesar. After Gnaeus was killed in 45 BC, Sextus survived another decade and established a naval power base in Sicily before being defeated in the Bellum Siculum and executed.
While in Africa Province resisting Caesar, Cato rebuked Gnaeus by telling him his father had accomplished much more at his age. The criticism prompted Gnaeus to launch an independent attack on Mauretania, which ended in defeat at the Battle of Ascurum.