The historian Henri Pirenne believed that the fall of Rome was due to the arrival of the Saracens, who he claimed cut off trade and thus divided the West from the East.  In Muhammad and Charlemagne Pirenne suggests that until the arrival of the Saracens in the late 700's A.D., all continued as usual in Roman civilization.  Since the time of Pirenne's writings in the 1930's, several historians have found flaws in his work.  In Origins of the Medieval World, William Carroll Bark punches gaping holes in the Pirenne thesis and presents proof for the argument that by the time of the Saracens Rome was long gone.  What emerged before the 700's, he contests, is responsible for the state of the world as we know it.
		Bark claims that transformation actually began with the Merovingians in the 400's A.D.  This family of French rulers inherited what was the most comprehensive tax system of the time.  Despite this enormous source of income, the Merovingians abandoned the land tax.  Incompetence is most likely the culprit here.  The only reason for abandoning such a well built system is the inability to make it work, and this could only have come about by a collapse in the education of civil servants. Even if the Merovingians could have operated their tax system, there would have been little use for it.  By the 400's the money supply contained little gold and was instead comprised of copper gold-dipped coins whose worth was substantially less. Traders soon preferred to barter in tangible goods (crops, animals, and possibly slaves).  In any case, abandonment of the land tax allowed for the formation of large estates, which resulted in the manorial system taking root in France.  The Merovingians were thus a cause and effect of Roman decline.
		Apathetic rulers weren't the only ones to blame.  The sacking of Rome in 410 A.D. by Alaric was a devastating blow to the civilization.  As countless civil wars had proven, Italy was hard to defend.  The barbarians had steadily been streaming into Italy since 378 A.D., when the Eastern emperor gave the peninsula to the Goths after the Battle of Adrianople.  As the barbarian invasions of Italy increased, the wealthy patricians and Equites found more and more reason to leave the country.  For them, the only place to go was east.
		The East's appeal had slowly been rising.  Fearing the wrath of the deadly Praetorian Guard, the emperor Diocletian left Rome and headed to the Eastern city of Split on the Dalmatian Coast in 284.  As the situation in the West deteriorated over the following centuries, the wealthy and educated bureaucrats, called curiales, abandoned it to the barbarians and the poor, taking with them their knowledge of how to maintain a working society.  Roman leaders attempted to rectify this "brain drain" by making civil positions hereditary.  Their plan backfired as more and more curiales, looking to escape mandatory work assignments, fled east in search of freedom.  Those who were wealthy enough to have built a library were sure to take it with them, and so the West also lost its supply of books.
			Of course, one book managed to stay afloat in post-apocalyptic Rome.  The Holy Bible had a long history with the Roman Empire by the time of Diocletian.  While he may have been unique in his reforms, Diocletian was just another emperor when it came to persecution of the Christians.  The torment of the followers of Christ was an active part of the Empire until 313 A.D. when Constantine - who, contrary to Dan Brown's assertion in The Da Vinci Code, was a converted Christian - passed the Edict of Milan, which legalized Christianity.  Reasons for Constantine's declaration are speculative, but he was no doubt aware of how highly organized the underground Church was.  Christians of the time had gone so far as to create a "shadow government" complete with bishops, a title they stole from their Roman governors.  With the Edict of Milan, the shadow bishops soon became the real bishops, not only in charge of the running of the Church but the running of the government as well.  This was not only convenient but necessary, as many of the other men who were capable of administering complex institutions were making their way East.  By 325 A.D., Christianity was the official religion of the Empire.  As Rome dissolved, some church fathers sought to distance themselves from the state and establish the Church as an autonomous organization.  Almost immediately following the 410 sack of Rome, St. Augustine of Hippo began work on City of God, in which he urges participation in government, allegiance to God, and separation of church and state.  So began the domination by the Church and the Christian Lord.
		On Earth, however, a very different lord had taken power.  The combination of Merovingian tax breaks for the wealthy potentiores and the unemployment of the poor (who were described by Salvian in 440 A.D. as being "assassinated" economically (p.56)) led to the creation of manors, each headed by a lord.  The dichotomy of wealthy lords and lowly peasants created a new bifurcated society which differed from Roman culture because it lacked a middle class.  The growth of manors effectively meant the death of cities, and so each manor became self-sufficient and no longer needed the aid of Roman government.  The centrally based government had already lost revenue during the shift towards the natural economy, as taxes paid in natural goods could not be transported and stored as easily as money.  As a result, the government became massively decentralized, with each area ruling itself in a new system of particularism.
		The growth of the manor also meant the creation of new technology.  Previously, the great engineers of the Empire had set about designing roads, sewer systems, and aqueducts.  Manors, however, required no aqueducts.  Instead, the great minds of the time turned their attention to one field: farming technology.  The middle ages saw the invention of the horseshoe, the birth of the three field system at the hands of German monks, and the creation of the harness by the barbarians.  These new technologies substantially eased labor, eventually making slavery obsolete.  Medieval society then differed from Roman in that it managed to free itself from Rome's crippling system of mandatory servitude. New technology also allowed for greater productivity which later translated into a population growth that ended the middle ages.
		The contribution of the barbarians was not limited to the harness, impressive though it was.  To clarify, the so-called "barbarians" were a mix of Germans, Goths, Celts, Angles, Saxons, and Slavs displaced by the invasions of Attila the Hun in the East during the 5th century.  They were outsiders to Roman society and they instantly came to idolize its highly structured government (or what was left of it).  In 476 A.D, an impressed German invader named Odovacar successfully stole the throne of the emperor Romulus Augustulus.  Luckily, not all imitations were so severe.  The barbarians envied Rome's written laws.  Seeking to imitate the Empire the barbarians began to draft a Lex Barbarorum, or "law of the barbarians."  Not having a written language to call their own, the invaders wrote in Latin.  The Lex Barbarorum, however, is merely a generic term for the many different sets of laws that governed each region.  One such set, the Lex Anglea, is better known as English Common Law and forms the base of the present-day American legal system.
				The contribution of the Church in these turbulent times cannot be overstated.  In addition to employing the most intelligent men of the time, workers of the Church were excellent record-keepers in every sense of the word.  For example, we can decipher from the writings of St. Jerome in the 4th century that literacy had dropped.  Jerome's choice to translate the Bible into a lower-class Latin was due to his inability to write in a more sophisticated manner.  Jerome was intelligent, but his semi-literacy indicates the state of education and government by his time.  In the following century St. Augustine of Hippo wrote City of God and Confessions, both based largely in Plato.  For readers, the work of Augustine became an important source of the Hellenic philosopher as copies of Plato's books were exported by the rich or burned by the illiterate.  The writings of Plato's student Aristotle were rescued for the West by another Christian by the name of Boethius.  Boethius, after having been imprisoned by the successor of Odovacar, began work on the Consolation of Philosophy.  In this work, Boethius attempts to unite the conflicting thoughts of Plato and Aristotle.  Boethius was killed before he could finish it (526 A.D.), but it nonetheless became the West's only source of Aristotle for hundreds of years.  In the same century, other monks made equally impressive contributions.  St. Benedict wrote his regulum, thereby laying out a code of servitude which inspired his followers; Alcuin of York devised the Carolingian miniscule, basis of present day text; Columban collected and saved books in the basements of monasteries in Italy; Cassiodorus devised the seven liberal arts still used today; and Gregory the Great invented the Gregorian chant, i.e. the basis of Western music.  Gregory the Great also stopped sending money to his Eastern counterparts and from 590 to 614 A.D. used it to build monasteries, many of which housed saved manuscripts and copied books.  If not for the actions of the time's brilliant men, the coming of the Renaissance is unimaginable.
			Not all monks were brilliant and even the duller ones managed to contribute something.  It was German monks who invented the three field system, as well as monks who built the monasteries and copied the books.  Benedictine monks were workers and farmers whose stoicism and devotion to labor impressed the barbarians.  These laborious monks converted pagan Europe to Christianity, the effects of which cannot be overstated.
				Pirenne, though accomplished in other fields of history, did himself an injustice in Muhammad and Charlemagne.  His miscalculations were most likely due to a desire to downplay the impact of the Germans on history.  Pirenne was, after all, from Belgium and wrote on the eve of World War II.  Thanks to the work of Bark, Pirenne's selective history is discredited.  Readers can see that Western civilization is truly a product of dying Roman culture encountering barbarian hosts, all set to the backdrop of Christianity.