This emperor’s original cognomen came from an ancestor whose beard supposedly turned reddish-bronze after Castor (-5[1])and Pollux stroked it. This emperor agreed to a peace treaty in which Tiridates I became king of Armenia, but had to travel to Rome for his crown. This emperor was praised in graffiti along with his wife Poppaea after he imposed height limits on tenements. When the Praetorian Guard (-5[1])under Tigellinus switched sides to Galba, this emperor committed suicide (10[1])and the Year of the Four Emperors began. (10[1])This final Julio-Claudian emperor (10[1])ordered the death of his mother Agrippina (10[1])the Younger (10[1])and his tutor (10[1])Seneca. For 10 points, which emperor persecuted Christians after the Great Fire of Rome? ■END■ (10[3])