History of the Roman Empire
Theodosius was the last Emperor who ruled over the whole Empire. After his death in 395, he gave the two halves of the Empire to his two sons Arcadius and Honorius; Arcadius became ruler in the East, with his capital in Constantinople, and Honorius became ruler in the West, with his capital in Milan and later Ravenna. The Roman state would continue to have two different emperors with different seats of power throughout the 5th century, though the Eastern Romans considered themselves to be the only ones who were fully Roman. Latin was used in official writings as much as, if not more than, Greek and the two halves were nominally, culturally and historically, if not politically, the same state.
2nd century
Early in the century, the Roman Empire attained its greatest expansion under the emperor Trajan, but after his death became primarily defensive for the rest of its history. Much prosperity took place throughout the empire at this time, ruled as it were by the Five Good Emperors, a succession of well-received and able rulers.
This period also saw the removal of the Jews from Jerusalem during the reign of Hadrian after Bar Kokhba's revolt.
The last quarter of the century saw the end of the period of peace and prosperity known as the Pax Romana at the death of the emperor Marcus Aurelius, last of the "Five Good Emperors", and the ascension of Commodus.