Mark Antony and Cleopatra and the Sergii family brothers participated in what battle?
Arch of the Sergii:  The arch commemorates three brothers of the Sergii family, specifically Lucius Sergius Lepidus, a tribune serving in the twenty-ninth legion that participated in the Battle of Actium and disbanded in 27 BC . Battle of Actium: The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic, a naval engagement between Octavian and the combined forces of Mark Antony and Cleopatra on 2 September 31 BC, on the Ionian Sea near the promontory of Actium, in the Roman province of Epirus Vetus in Greece.
Battle of Actium