Constantine {Ans: First Christian emperor. He legalized Christianity, destroyed the Tetrarchy, and reunited the empire under one emperor.}Crisis of the Third Century {Ans: Fifty years of political instability, economic decline, plague outbreaks, and barbarian invasions following the end of the Pax Romana.}Tiberius {Ans: Augustus's heir who had been a great general but as emperor spent so much time on vacation that one of his generals, Sajanus, virtually took control of the government--until this emperor had him executed.}Alexandria {Ans: Major city in the Egyptian province. Home of Cleopatra.}Alaric {Ans: Barbarian and former Roman commander who led the Visigoths to sack Rome for the first time in 800 years.}Pax Romana {Ans: Two-hundred year time of relative peace beginning with Augustus and ending with Marcus Aurelius.}