Julius Caesar was almost certainly based upon Plutarch's Lives, a compendium of biographies published in the first century CE and translated into English during Shakespeare's life. Much of the plot of Julius Caesar, and even the lines attributed to certain characters, are derived more or less straight from Plutarch. So, in many ways, the question is how true Plutarch was to facts—and this is very difficult to ascertain, given that Plutarch is one of the most important sources for the life of Julius Caesar as a historical figure. That said, one major deviation from the historical record is that Shakespeare collapsed nearly three years of events, from Caesar's assassination to the battle of Philippi, into a few days, for the purpose of maintaining the flow of the play. Shakespeare also emphasizes the virtues of Brutus, relative to the other conspirators, more than Plutarch does. Even Caesar himself comes off as a more sympathetic character in the play than history might allow—there is talk that Caesar is "ambitious" but little detail about the political (and military) maneuvering that he undertook to put himself in the position to effectively rule over Rome.