Simplify the following text for a Grade 9 native English-speaking person.
Original: Led by Gaius Cassius Longinus and Marcus Junius Brutus , they stabbed Julius Caesar to death in the Theatre of Pompey on the Ides of March ( March 15 ) 44 BC .
Simplified: The conspirators stabbed Caesar to death in the Theatre of Pompey on the Ides of March , 15 March 44 BC .