Secondly the decline of the empire wasn’t something which started and ended suddenly. It was a progressive mutation which began long before Constantine and ended well after the last emperor, Romulus Augustulus, was deposed.
The great increase in Christian thought and belief accompanied the fall of the Roman Empire of the West. Following the death of Theodosius the Great in the year 395AD the Empire was divided into East and West amongst his sons.
The evolution of Christianity meant that many churches such as Santa Sabina were built in the city during this period but it is also true that many of the important buildings of the classical period were left to crumble or to be quarried for building materials.
The Empire of the West was in great economic difficulty. Power was in the hands of the landowners and of the Roman military who were often not even of Roman provenance. The Christian church constituted a political power of opposition to the existing regime and the population was in general decline. This meant that the Emperor ruled with great difficulty.
The penetration of barbarian peoples into the Western Empire became increasingly easy and with it came a progressive weakening of Imperial control reducing it to a dominion over Italy itself.
In comparison to this, the Empire of the East had good finances, supported by a functioning bureaucracy and clear Imperial control over the church and military. Incursions into its dominions were rare and commerce was strong. Latin language was gradually replaced by Greek which in the year 440 was recognised as the new official language in administrative circles. In many ways this symbolised the true separation of the Eastern and Western parts of the Empire.
In the West the barbarian general Stilicho faithful to Emperor Honorius successfully defended Italy from various barbarian incursions. However Honorius was fearful of Stilicho’s growing power and had him put to death. Bad move. On hearing of Stilicho’s demise successive barbarian attacks such as the sack of Rome by the Visigoths under Alaric in 410 brought Rome and the Empire of the West to a state of collapse. The civilised world was aghast. A number of barbarian dominions formed declaring themselves under Imperial dominion but actually not recognising Rome’s sovereignty.
In the mean time the Huns under Attila were invading the West from the East. They drove through many lands and came to Gaul, now France. The Romans still regarded Gaul as a province of the Empire although in reality large parts were governed by a tribe called the Franks. The governor of Orleans, a Roman general called Aetius came to peace with the warring Goths and Franks. Together on the plain of Chalons , in the year 451 they waged war against Attila and the Huns.
This was one of the fiercest battles ever known and had the Huns won it can be said that it would be they and not the partly Christianised Goths and Franks to become the strongest power of the following centuries with obvious consequences to the progress of Western civilisation. Attila was not completely defeated and continued some progress into Italy, taking the city of Aquileia. Many citizens fled and built a settlement on a marsh. This settlement was later to become the mighty republic of Venice.
In spite of the great victory over Attila, Rome was invaded and sacked by the Vandals, distant cousins of the Goths, in the year 455AD. The death of Emperor Valentinian III marked the end of the Empire although its official demise is accepted as being the forced abdication of the young, last, Emperor of the West, Romulus Augustulus, in the year 476AD.
The following pages give further insight into the reasons for the decline and fall of the Roman empire:
link to: society after the fall of the roman empire