text: To protect the Iazyges, this emperor ordered the construction of a fortification system called the Devil'sDykes.
full_question: To protect the Iazyges, this emperor ordered the construction of a fortification system called the Devil'sDykes. One of the best examples of spolia, or the reusing of earlier sculptural reliefs, is this emperor'striumphal arch next to the Colosseum. For unclear reasons, this man ordered his wife Fausta to besuffocated in an overheated bath. At the battle of Chrysopolis, this ruler, the first to use the (*) labarum,prevailed over his rival Licinius. This man gazed skyward and saw the phrase "In this sign, you shall conquer,"inspiring him to adopt the Chi-Rho standard to victory over Maxentius at the Battle of Milvian Bridge. This manbuilt his new capital on the site of ancient Byzantium. For 10 points, name this first Christian Roman emperor.
first_sentence: To protect the Iazyges, this emperor ordered the construction of a fortification system called the Devil'sDykes.
raw_answer: Constantine the Great [or Constantine I; or Flavius Valerius Aurelius Constantinus Augustus] 