Abstract For the Roman Republic, the evidence on voting and elections is scarce, vague and rather incidental. Most of data shows, on a daily basis, a sharing responsibility between the Senate and the presiding magistrate. But, in the last century of the Republic, despite some strategies to avoid it, such control became less categorical. In time, when the customary inertia had vanished, the Mars Field became a looking-glass in which the crisis of the oligarchy was refl ected. In the Principate, however, the Emperor regained control over the elections, as they were no longer under the auctoritas of the Senate and the president’s imperium, but under the Princeps’ own power. Keywords: tribus, centurias, praerogativa, comitia, ballots.