The legions of Trajan, in the early second century, moved in two directions: Dacia, which was reduced to province in 107, and the border areas with the Kingdom of the Parties. But in those regions Trajan, in 116, was just able to start the organization of only three new provinces (Armenia, Assyria, Mesopotamia). His successor, Hadrian, decided, in 117, to renounce the new territories, in order to prevent the conflict between Asian kingdoms and the Roman world, starting the policy of coexistence with the East that continued for over a century.
In the map the dark green indicates the extension of the empire after the retreat decided by Hadrian, the second color indicates the Asian provinces in which the legions of Trajan penetrated between the 115 and the 116, the green light color indicates the Kingdom of the Parties. On the coasts of the Crimea stretched a "protected" kingdom (Regnum Bosphori). The "Towers" indicate the main stable garrisons placed outside of the borders.
The map shows (with many approximations) the situation in the second century AD, when Hadrian renounced to the new conquered regions on the persian borders, and was establishing, among the four great empires, a state of coexistence based on slave economy. The four empires are, in addition to the Roman (red), the Parthian one(blue), the Indian Kushana (green), the Chinese Han (yellow). It's indicated the Silk Road (red), which from Ch'angan through Kutsha and Baktra, reached Ctesiphon and Antioch, and from there to Rome, with a detour to Minigara. Another traffic route( black ), started from the Chinese port of Fanju , through the waters of Indonesia and Ceylon, reached Minigara, and from there, through the coasts of Arabia and Aksum Sabaean, came up to Petra and Antioch. It's indicated the region where the meetings between worlds so remote were the most frequent (the Baktriana). In addiction, written in red, are marked at the edge of the great empires, some minor states: in Asia, the Kingdom of Silla (Korea), the Fu-Nan, Chola, Ceylon and Saudi Sabaean; in Africa, the Kingdom of Meroe and the Kingdom of Aksum; in Europe, the Kingdom of Tara in Ireland and the Kingdom of the Bosporus. Moreover, the African region where flourished, since the fifth century BC, the "culture" of Nok. Finally, in black, are shown the major Asian nomadic populations, fated to disrupt the structure of the ancient world in later centuries, as the Huns, Mongols and Tatars.
The darker areas indicates regions within the empire, in the age of Constantine, where about a half of the population was Christianized. The second color shows areas of significant spread of Christianity (particularly in Egypt and in the territory of Carthage). The lighter color, indicates areas of low prevalence. The unstained areas, indicates the areas where the new cult had not yet penetrated. The map confirms that the spread of Christianity was relatively low, and indicates the locations where edicts had benn issued and where the major ecumenical councils took place: from Milan to Thessaloniki, from Nicaea to Constantinople to Ephesus and Chalcedon. The arrow indicates the direction in which propagated the followers of the Nestorian heresy (condemned at the Council of Ephesus). The Nestorians, having found refuge in the Persian Empire, reached the very remote China, where their diffusion is evidenced by the stele of Singanfu. The map shows the final division of the empire between Arcadius and Honorius (vertical black line), in 395. Since 402 is the capital of the Western Empire was moved to Ravenna.
The map corresponds to the year of Theodoric's death and indicates the situation before the "Empire Restoration" attempt by Justinian. The first barbarian appropriations were in the Iberian Peninsula were people of Swabian and vandale. This were followed by the penetration of the Goths, with the allocation of the Western Goths (or Visigoths) in Spain and Eastern Goths (or Ostrogoths) in Italy. The Swabian kingdom survived for some time in western Spain. Unrelated to the Germanic invasions must be considered the Britons kingdoms, that were formed in minor Britain and major Britain (Wales), where the ancient Celtic peoples resisted to the Germanic invasions, recovering the loss of autonomy due to the Roman conquest.