People needed water to drink; it was vital for agriculture;
And it provided a rapid and economical means for transporting people and goods. Some of the most impressive technological achievements of ancient Rome and China involved hydraulic (water) engineering.
Roman cities, with their large populations, required abundant and reliable sources of water. One way to obtain it was to build aqueducts—stone channels to bring water from distant lakes and streams to the cities. The water flowing in these conduits was moved only by the force of gravity. Surveyors measured the land's elevation and plotted a course that very gradually moved downhill.
Some conduits were elevated atop walls or bridges, which made it difficult for unauthorized parties to tap the water line for their own use. Portions of some aqueducts were built underground. Still-standing aboveground segments indicate that the Roman aqueducts were well-built structures made of large cut stones closely fitted and held together by a cement-like mortar. Construction of the aqueducts was labor-intensive, and often both design and construction were carried out by military personnel. This was one of the ways in which the Roman government could keep large numbers of soldiers busy in peacetime.
Sections of aqueduct that crossed rivers presented the same construction challenges as bridges. Roman engineers lowered prefabricated wooden cofferdams—large, hollow cylinders—into the riverbed and pumped out the water so workers could descend and construct cement piers to support the arched segments of the bridge and the water channel itself. This technique is still used for construction in water.
When an aqueduct reached the outskirts of a city, the water flowed into a reservoir, where it was stored. Pipes connected the reservoir to different parts of the city. Even within the city, gravity provided the motive force until the water reached the public fountains used by the poor and the private storage tanks of individuals wealthy enough to have plumbing in their houses.
In ancient China, rivers running generally in an east-west direction were the main thoroughfares. The earliest development of complex societies centered on the Yellow River Valley, but by the beginning of the Qin Empire the Yangzi River Valley and regions farther south were becoming increasingly important to China's political and economic vitality. In this era the Chinese
Who regarded their refusal to worship the emperor as a sign of disloyalty. Despite occasional government-sponsored attempts at suppression and spontaneous mob attacks, or perhaps because of them, the young Christian movement continued to gain strength and attract converts. By the late third century c. e. its adherents were a sizable minority within the Roman Empire and included many educated and prosperous people with posts in the local and imperial governments.
The expansion of Christianity should be seen as part of a broader religious tendency. In the Greek Classical period a number of “mystery” cults had gained popularity by claiming to provide secret information about the nature of life and death and promising a blessed afterlife to their adherents. In the Hellenistic and Roman periods, a number of cults making similar promises arose in the eastern Mediterranean and spread throughout the Greco-Roman lands, presumably in response to a growing spiritual and intellectual hunger not satisfied by traditional pagan practices. These included the worship of the mother-goddess Cybele in Anatolia, the Egyptian goddess Isis, and the Iranian sun-god Mithra. As we shall see, the ultimate victory of Christianity over these rivals had as much to do with historical circumstances as with its spiritual appeal.
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Interactive Map: The Expansion of Christianity to 600
The Magic Canal Engineers of Shi Huangdi, "First Emperor" of China, exploited the contours of the Landscape to connect the river systems of northern and southern China. (From Robert Temple, The Genius of China [1986]. Photographer: Robert Temple)
Began to build canals connecting the northern and southern zones, at first for military purposes but eventually for transporting commercial goods as well. In later periods, with the acquisition of more advanced engineering skills, an extensive network of canals was built, including the 1,100-mile-long (1,771-kilometer-long) Grand Canal.
One of the earliest efforts was the construction of the Magic Canal. A Chinese historian tells us that the Qin emperor Shi Huangdi ordered his engineers to join two rivers by a 20-mile-long (32.2-kilometer-long) canal so that he could more easily supply his armies of conquest in the south. Construction of the canal posed a difficult engineering challenge because the rivers Hsiang and Li, though coming within 3 miles (4.8 kilometers) of one another, flowed in opposite directions and with a strong current.
The engineers took advantage of a low point in the chain of hills between the rivers to maintain a relatively level grade. The final element of the solution was to build a snout-shaped
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Mound to divide the waters of the Hsiang, funneling part of that river into an artificial channel. Several spillways further reduced the volume of water flowing into the canal, which was 15 feet wide and 3 feet deep (about 4.5 meters wide and 1 meter deep). The joining of the two rivers completed a network of waterways that permitted continuous inland water transport of goods between the latitudes of Beijing and Guangzhou (Canton), a distance of 1,250 miles (2,012 kilometers). Modifications were made in later centuries, but the Magic Canal is still in use.
The relative ease and safety of travel brought by Roman arms Transformation and engineering enabled mer
Chants to sell their wares and helped the early Christians spread their faith. Surviving remnants of roads, fortification walls, aqueducts, and buildings testify to the engineering expertise of the ancient Romans. Some of the best engineers served with the army, building bridges, siege works, and ballistic weapons that hurled stones and shafts. In peacetime soldiers were often put to work on construction projects. Aqueducts—long elevated or underground conduits— carried water from a source to an urban center, using only the force of gravity (see Environment and Technology: Water Engineering in Rome and China). The Romans were pioneers in the use of arches, which allow the even distribution of great weights without thick supporting walls. The invention of concrete—a mixture of lime powder, sand, and water that could be poured into molds—allowed the Romans to create vast vaulted and domed interior spaces, unlike the rectilinear pillar-and-post designs of the Greeks.
Defending borders that stretched for thousands of miles was a great challenge. In a document released after his death, Augustus advised against expanding the empire because the costs of administering and defending subsequent acquisitions would be greater than the revenues. The Roman army was reorganized and redeployed to reflect the shift from an offensive to a defensive strategy. At most points the empire was protected by mountains,
Roman Aqueduct Near Tarragona, Spain How to provide an adequate supply of water was a problem posed by the growth of Roman towns and cities. Aqueducts channeled water from a source, sometimes many miles away, to an urban complex, using only the force of grav'ty. To bring an aqueduct from high ground into the city, Roman engineers designed long, continuous rows of arches that maintained a steady downhill slope. Roman troops were often used in such large-scale construction projects. Scholars sometimes can roughly estimate the population of an ancient city by calculating the amount of water that was available to it. (Robert Frerck/Woodfin Camp & Associates)
Deserts, and seas. But the lengthy Rhine and Danube river frontiers in Germany and central Europe were vulnerable. They were guarded by a string of forts with relatively small garrisons adequate for dealing with raiders. On particularly desolate frontiers, such as in Britain and North Africa, the Romans built long walls to keep out the peoples who lived beyond.
Most of Rome’s neighbors were less technologically advanced and more loosely organized, and they did not pose a serious threat to the security of the empire. The one exception was the Parthian kingdom, heir to the Mesopotamian and Persian Empires, which controlled the lands on the eastern frontier (today’s Iran and Iraq). For centuries Rome and Parthia engaged in a rivalry that sapped both sides without any significant territorial gain by either party.
The Roman state prospered for two-and-a-half centuries after Augustus stabilized the internal political situation and addressed the needs of the empire with an ambitious program of reforms. In the third century c. e. cracks in the edifice became visible. Historians use the expression “Third-Century Crisis” to refer to the period from 235 to 284 c. e., when political, military, and economic problems beset and nearly destroyed the Roman Empire. The most visible symptom of the crisis was the frequent change of rulers. Twenty or more men claimed the office of emperor during this period. Most reigned for only a few months or years before being overthrown by rivals or killed by their own troops. Germanic tribesmen on the Rhine/Danube frontier took advantage of the frequent civil wars and periods of anarchy to raid deep into the empire. For the first time in centuries,
Roman cities began to erect walls for protection. Several regions, feeling that the central government was not adequately protecting them, turned power over to a man on the spot who promised to put their interests first.
The political and military emergencies had a devastating impact on the empire’s economy. Buying the loyalty of the armies and paying to defend the increasingly permeable frontiers drained the treasury. The unending demands of the central government for more tax revenues from the provinces, as well as the interruption of commerce by fighting, eroded the towns’ prosperity. Shortsighted emperors, desperate for cash, secretly reduced the amount of precious metal in Roman coins and pocketed the excess. The public quickly caught on, and the devalued coinage became less and less acceptable in the marketplace. The empire reverted to a barter economy, a far less efficient system that further curtailed large-scale and long-distance commerce.
The municipal aristocracy, once the most vital and public-spirited class in the empire, was slowly crushed out of existence. As town councilors, its members were personally liable for shortfalls in taxes owed to the state. The decline in trade eroded their wealth, which often was based on manufacture and commerce, and many began to evade their civic duties and even went into hiding.
Population shifted out of the cities and into the countryside. Many people sought employment and protection from both raiders and government officials on the estates of wealthy and powerful country landowners. The shrinking of cities and movement of the population to the country estates were the first steps in a demographic shift toward the social and economic structures of the European Middle Ages—roughly seven hundred years during which wealthy rural lords dominated a peasant population tied to the land (see Chapter 10).
Just when things looked bleakest, one man pulled the empire back from the brink of self-destruction. Like many of the rulers of that age, Diocletian came from one of the eastern European provinces most vulnerable to invasion. A commoner by birth, he had risen through the ranks of the army and gained power in 284. His success is indicated by the fact that he ruled for more than twenty years and died in bed.
Diocletian implemented radical reforms that saved the Roman state by transforming it. To halt inflation (the process by which prices rise as money becomes worth less), Diocletian issued an edict that specified the maximum prices that could be charged for various commodities and services. To ensure an adequate supply of workers in vital services, he froze many people into their professions and required them to train their sons to succeed them. This unprecedented government regulation of prices and vocations had unforeseen consequences. A “black market” arose among buyers and sellers who chose to ignore the government’s price controls (and threats to impose the death penalty on violators) in order to establish their own prices for goods and services. Many inhabitants of the empire began to see the government as an oppressive entity that no longer deserved their loyalty.
When Diocletian resigned in 305, the old divisiveness reemerged as various claimants battled for the throne. The eventual winner was Constantine (r. 306-337), who reunited the entire empire under his sole rule by 324.
In 312 Constantine won a key battle at the Milvian Bridge over the Tiber River near Rome. He later claimed that he had seen a cross (the sign of the Christian God) superimposed on the sun before this battle. Believing that the Christian God had helped him achieve the victory, in the following year Constantine issued the Edict of Milan, ending the persecution of Christianity and guaranteeing freedom of worship to Christians and all others. Throughout his reign he supported the Christian church, although he tolerated other beliefs as well. Historians disagree about whether Constantine was spiritually motivated or was pragmatically seeking to unify the peoples of the empire under a single religion. In either case his embrace of Christianity was of tremendous historical significance. Large numbers of people began to convert when they saw that Christians seeking political office or favors from the government had clear advantages over non-Christians.
In 324 Constantine transferred the imperial capital from Rome to Byzantium, an ancient Greek city on the Bosporus" strait leading from the Mediterranean into the Black Sea. The city was renamed Constantinople", “City of Constantine.” This move both reflected and accelerated changes already taking place. Constantinople was closer than Rome to the most-threatened borders in eastern Europe (see Map 6.1). The urban centers and prosperous middle class in the eastern half of the empire had better withstood the third-century crisis than had those in the western half. In addition, more educated people and more Christians were living in the eastern provinces (see Chapter 10).
The conversion of Constantine and the transfer of the imperial capital away from Rome often have been seen as marking the end of Roman history. But many of the important changes that culminated during Constantine’s reign had their roots in events of the previous two
Bosporus (BAHS-puhr-uhs) Constantinople (cahn-stan-tih-NO-pul)
The Qin Unification of China, 221-206
B. C.E.
Centuries, and the Roman Empire as a whole survived for at least another century. The eastern, or Byzantine, portion of the empire (discussed in Chapter 10) survived Constantine by more than a thousand years. Nevertheless, the Roman Empire of the fourth and fifth centuries C. E. was fundamentally different from the earlier empire, and for that reason it is convenient to see Constantine’s reign as the beginning of a new epoch.
World History
