This emperor instituted civil reform in the provinces by creating the office of "corrector." He formalized his predecessor's social welfare program, the alimenta. This emperor defeated Decebalus at the Battle of Sarmisegetusa in modern-day Romania. He had several projects built by Apollodorus of Damascus, including his namesake Market and Forum. He annexed the Sinai Peninsula, Parthia, and (*) Dacia. This second of the Five Good Emperors was succeeded by Hadrian. For 10 
This emperor instituted civil reform in the provinces by creating the office of "corrector." He formalized his predecessor's social welfare program, the alimenta. This emperor defeated Decebalus at the Battle of Sarmisegetusa in modern-day Romania. He had several projects built by Apollodorus of Damascus, including his namesake Market and Forum. He annexed the Sinai Peninsula, Parthia, and (*) Dacia. This second of the Five Good Emperors was succeeded by Hadrian. For 10 points, name this Roman emperor at the beginning of the 100s, who is commemorated by a Column in Rome, and under whom the Empire reached its greatest extent.
This emperor instituted civil reform in the provinces by creating the office of "corrector."
Trajan [or Nerva Trajanus Divi Nervae filius Augustus; do NOT accept any name by itself unless that name is "Trajan"]