Guaporense

The history of Classical Civilization can be divided into two broad periods: the period in which it was rising and the period in which it was failing. From 800 BC to the time of Augustus, the civilization of the cities of the ancient Mediterranean was in the process of increasing sophistication of technology, economic development, demographic development, etc. From the time of Augustus to the 2nd century, it was apparently in a situation of relative peak and stagnation; then, from the mid-2nd century onwards, it started to collapse. This collapse occurred over all dimensions of society, and it even affected the production of artworks like busts. In Pompeii submerged by a volcanic eruption in 79 AD, during the economic peak of the ancient world, there are busts of common citizens of the town which were not even very rich but had their own busts, such as this banker:

There is no evidence that Huns ever were close to any of the Chinese kingdoms that existed at the time (in the 4th-5th centuries, there were many kingdoms in what today we call China:

My study is for the Early Roman Empire around 100 AD. Iberia was not heavily urbanized, considering it did not have many large cities compared to the size of the Iberian Peninsula. Archeological surveys suggest that Sicily had a comparable urban population to Iberia. I have used demographic estimates by Scheidel (2009) adjusted with other references (he appears to overestimate the population of Roman Iberia, considering the small urban population and other sources yield more conservative estimates for the Iberian population). Overall the Roman Empire had 65 million, excluding client states/provinces like Bosphorus, Armenia, Dacia, and Mesopotamia. Iberia was indeed huge, so its total population could not have been much smaller than around 5-6 million. Hence, its overall rate of urbanization was certainly pretty low compared to the rest of the Roman Empire. According to this framework, the city of Rome had 923,000 inhabitants, which can be thought of as slightly lower than typical estimate for Rome (about 1 to 1.2 million).For Pompeii, my estimate is 8,900 people, which is also slightly lower than the typical estimate around 11,000 to 12,000. Overall, according to these estimates, you had about 35 million people in the Western Half of the Roman Empire and 31 million in the Eastern Half. The urbanization rate was slightly higher in the Eastern Half, 17%, versus 15% in the Western Half. So perhaps the difference in development (as indicated by urbanization rates) between the two halves was not large enough to explain alone why the Eastern half of the Roman Empire lasted longer—the fact it was more defensible also important.

Been listening to a lot of Iron Maiden lately, one of their most underrated songs IMO:

I am actually working on a scientific paper regarding urbanization levels across the Roman Empire and Classical Greece. My methodology is based on archeological evidence. My conclusions so far: 1) The Classical Greek world was substantially more urbanized than any region of the Roman Empire (but the difference in rates of urbanization was smaller than estimated before, Roman Greece in particular was almost as urbanized as Classical Greece). 2) Roman Greece and Greek-speaking regions of Crete, Sicily, Cyrenaica, and the western part of Asia Minor were the most urbanized. 3) The ranking of urbanization rates by region is the following: 1. Mainland Greece, Sicily, Crete, and Cyrenaica (most urbanized) 2. Italy 3. Egypt (it was very urbanized, possibly be more urbanized than Italy) 4. Asia Minor and North Africa (roughly the same rate of urbanization in both regions, however Asian Minor population estimates include large rural populations in the interior of the region) 5. Syria 6. Gaul 7. Balkan provinces north of Greece, bordering the Danube 8. Iberia (surprisingly, it is mostly not urbanized although there were many cities in Baetica) 9. Britain (least urbanized) Rates of urbanization are estimated in terms of the proportion of the population living in cities with at least 5,000 inhabitants (smaller towns like Herculaneum and Priene do not count as urban by this method, but I had to use a high cutoff because archeological information regarding smaller towns is very incomplete). About 1/6 people in the Roman Empire lived in such larger towns and cities, with nearly 1/4 or 1/3 in the most urbanized regions and 1/20 in the least urbanized regions. This is a map of 885 surveyed Roman cities scaled by the estimated size of their geographical areas, which I used to make my estimates: Out of the 15 biggest cities among those cities with measured areas, 12 were Greek cities (often Hellenistic colonies), while 11 were in the Eastern Provinces and 4 were in the Western Provinces. In terms of East vs West, the rates of urbanization are not that different because Sicily, North Africa, and Italy were highly urbanized. While Gaul, Iberia, and Britain were not very urbanized.

The Eastern Roman Empire had the most urbanized and richest provinces. This was a product of the fact that most Classical Greek cities were in the Eastern Mediterranean; below is a map with the ca. 900 Ancient Greek city-states in which we know their geographical location (POLIS (stanford.edu)); notice how the regions populated by a large number of Greek cities closely matches the territory of the Byzantine Empire around the year 1000: While Romanization resulted in significant development in the Western half of the Roman Empire, it is still true that the Western half never reached the same degree of development as the Eastern half. Hence, when the Roman Empire was broken into two halves, the most developed half lasted a thousand years longer. I wouldn't think it is particularly due to Constantinople being hard to conquer, while it being a fortified bastion helped to deter critical attacks; it's also true that the Byzantines held over much more land than just Constantinople for most of the thousand years they outlasted the western empire. So, I think the East's survival was mainly due to a combination of being: (1) Having more developed lands that could pay more taxes, so they were capable of supporting more, better trained, and equipped soldiers. (2) These lands were in strategic positions that were more defensive (in particular, the city of Constantinople, but also the provinces of the Eastern Roman Empire had a smaller frontier with the northern European tribes. And the Sassanid Persians, despite their historical enmity with Rome, were a bit less dangerous than the Northern European tribes (in my evaluation).

If you take a look at that book can you give some background on the people they call scientists. Basically, it says that in modern times we have the development of modern science, in antiquity they did not develop modern science, but there were people who were doing work that today we would call science. The largest number of such people were active during the Late Republic and Early Imperial periods. In regards to technology, there was very substantial technological progress from the time of the Early Republic to the Early Empire. For example, in 300 BC there did not exist watermills (which were the biggest technological advance in energy technology until the Watt's steam engine in the late 18th-century), keyboard instruments, mechanical geared devices, nor domes, nor sophisticated concrete structures or arched structures. All these were invented over the next few centuries. As a result, the Pantheon build in the early 2nd century AD would be science fiction for people living at the time of the First Punic War. Other technologies invented during this period include the heavy plow (the Romans described it being used in the heavy soil of Roman Gaul and Germania) and the Gallic mechanical reaper. This old scientific american article from 1979 is a good description of how ancient catapult technology evolved: Ancient Catapults on JSTOR

They say that regarding the general situation of the ancient world as a whole rather than individual cities. In the case of Constantinople, it grew because the emperor moved the capital there, so it grew much larger, despite the overall decrease in urban population across the empire compared to the level a few centuries earlier.

Well, it's generally agreed by specialists that Classical civilization as a whole (that is, the civilization that was unified under the Roman Empire) started to decline (in economic, technological, and demographic terms) around 100-150 AD. With the economic decline and decline of long-distance trade, cities started to lose population as well, while people migrated to the countryside to live as self-sufficient farmers. This process took several centuries, and the end was the creation of the medieval world. Rome's population collapse was more dramatic than other cities because it was much bigger (partly thanks to subsidized foot and entertainment paid by the provinces), but it was just part of a general trend: the fact is that it continued to be the largest city in Western Europe until the rise of Cordoba in the 10th century.

Actually, there was a lot of scientific progress from 600 BC to around the of Augustus, then the number of scientists peaked in the first 150 years of the Roman Empire. After the early 2nd century AD, the number of documented scientists collapsed. This is documented in the number of recorded cases of ancient scientists from Keyser and Irby-Massie (2012), who recorded a timeline of about 2,000 ancient scientists (mostly Greek and Roman, but also some Persian and Jewish authors as well, see Amazon.com: Encyclopedia of Ancient Natural Scientists: The Greek Tradition and its Many Heirs: 9780415692632: Keyser, Paul T., Irby-Massie, Georgia L.: Libros): Technology also made substantial progress in Classical Antiquity. For example, buildings like the Pantheon would be inconceivable a few centuries earlier (and also became impossible to build after the fall of Rome until relatively modern times). Then, scientific and technological progress stopped during the period of the greatest power of the Roman Empire due exactly to the centralization of power in the emperor. Alain Bresson (2016) indeed blames the centralization of power into the Roman Empire for killing the institutional foundations of Classical society, which was the autonomous city-state. Ancient science and technology progressed a lot during the Archaic, Classical, and Hellenistic periods, the age of city-states, and even during the beginning of Roman hegemony, cities around the Mediterranean world continued to function as city-states, operating independently of Rome except that they didn't start wars with each other (unlike the Classical period), so scientific and technological progress continued, peaking around the time of Augustus. It was the gradual centralization of power in Rome, starting with the Social War in the early 1st century BC, which incorporated all of peninsular Italy into Rome, and finishing with the centralized bureaucratic empire of Late Antiquity, that killed independent thinking and, therefore, hindered further scientific and technological progress. After the prosperity of the Early Imperial period (which economic historian Peter Temin states, Early Imperial Rome was likely the most prosperous society that existed before the Industrial Revolution), it took about 500-600 years of slow but dramatic economic and demographic decline for the Roman Empire to lose most of its territories, becoming the tiny Byzantine state of the early 8th century. By then, however, cities across the Mediterranean were mostly abandoned, long-distance trade in bulk commodities disappeared, and there were no economic resources available to support scientists in advancing the knowledge accumulated by the ancients. Then it took about a thousand years for the European population densities to surpass the Roman peak, and with economic recovery, particularly in the city-states of Italy and the Hanseatic League to the north, the Renaissance blossomed. Still, in the 17th century, the famous mathematician Leibnitz cited Apollonius of Perga from about 200 BC as an example of cutting-edge mathematics. Thus, it was only in recent centuries that modern western civilization fully surpassed the ancients.

I recommend Mogens Herman Hansen's work, in particular, his work on the Athenian Democracy and on the Classical Greek City state: Amazon.com: Polis: An Introduction to the Ancient Greek City-State: 9780199208500: Hansen, Mogens Herman: Libros Which made me think that city-state societies tend to be more modern and dynamic than traditional societies of territorial states. In Medieval Northern Italy, there emerged a society of 300 city-states, of which cities like Florence and Venice were the largest. Connected to the mediterranean sea, these city-states traded a lot and achieved a very high level of economic prosperity so that by the 14-15th centuries, Northern Italy was (likely) the richest region on the planet. When people achieve a relatively high level of economic development, they have more free time to think about ideas and to work in art. That is why artistic flowering are strongly correlated with periods of economic prosperity (such as the artistic flowering in Late Classical, Hellenistic, and Early Imperial Roman art, Renaissance Italy, and Golden Age Netherlands).

The Roman Empire was formed as a thalassocratic empire: it was basically formed as a network of city-states around the mediterranean sea under the hegemony of the city-state of Rome. This empire expanded towards the northwest of Europe, as this region was very close to the Mediterranean region with direct access from the region of Gallia transalpina, where Julius Caesar based his invasion of Gaul. Most Roman wars were not wars of conquest but instead wars for the security and hegemony of Rome. As noted by many authors, the empire of Rome was formed slowly in these defensive wars. Even Caesar's conquest of Gaul was defensive: he responded to the request for the defense of the southern gallic tribes around the region of Gallia Narbonensis (already a Roman province). Trajan's invasion of Parthia was something very different. Not a defensive war; it was an attempt at invading the Parthian Empire, which was a Central Asian empire controlled by semi-nomadic horse archers. One should note that most of the border between Roman and Parthian territories was desertic, except for some small inhabitable areas around the Tigris river. Thus, it did not make any sense to annex territories there. This invasion also had no defensive purpose, as Syria was not under Parthian military threat for over a century: Trajan invaded it for the glory of doing so. Once he died, Hadrian took office, and he quickly abandoned Trajan's conquests. I should also note that Trajan's Parthian campaign is not well documented in our sources.

As I already stated in another post, the time around 1 AD was a period of peak economic prosperity for the Mediterranean world and so they imported large quantities of exotic goods from faraway places. The Classical civilizations of Greece and Rome had more awareness of the existence of India than of China (which was geographically separated from the rest of Eurasia by the Himalayan Mountain range), as Alexander the Great himself had conquered a substantial portion of the Indian subcontinent.

Among historians specialized in the subject, there are two views: the small Rome view, which states that Rome had about 500,000 to 600,000 inhabitants, and the big Rome view, which states it had around 1 million people or even more. The small Rome view comes from the fact that Imperial Rome had a walled area of 1,373 hectares which is enough for 500,000 people at twice the density estimated for Pompeii (the city of Pompeii had walls enclosing 66 hectares and a population of around 11,000-12,000). However, excavations in Ostia, Rome's port city, show that densities much higher than Pompeii were possible, apartment buildings typically had 3-4 floors in there, in Rome proper they were even bigger (bigger cities means taller apartment buildings because land becomes more valuable, Augustus regulated building codes stating heigh limits for insulae at 70 Roman feet, enough for 6-7 floors): In addition, we know that Augustus' division of Rome into 14 regions covered a substantially larger area than the Aurelian walls (built in the late 3rd century, when the city of Rome had declined in population from its peak during the time of the Late Republic and Early Empire). Based on the archeological evidence and Augustus', Hanson and Ortman's (2017) model estimates that Rome had 923,000 inhabitants, very close to the 1 million figure typically estimated. (PDF) A systematic method for estimating the populations of Greek and Roman settlements (researchgate.net) We should also consider that Rome had substantial suburban neighborhoods, as well as ancient writers describe the lack of clear distinction between the city and the countryside, stating that Rome looked like it could stretch forever. The ca. 900,000 figure might be accurate for the city center. Still, there were hundreds of thousands of people living in the suburbs, so Rome's ancient metro area might have approached something like 1.5 million around the 1st century. Thus, the city of Rome's likely population history in antiquity was: 500 BC: 15,000 (about 30,000 in the city-state, according to Walther Scheidel's estimate in his 2019 book) 300 BC: 90,000 (from Beard (2016), 1 million citizens in the whole city-state) 225 BC: 150,000 (from Keith Hopkins) 30 BC: 900,000 (big jump in growth following the Punic Wars and the conquest of the ancient mediterranean, Rome surpassed Alexandria to be the largest city in the Ancient World, Keith Hopkins estimate Rome approached 1 million people by the time of Augustus) 50 AD: 1,200,000 (perhaps the peak was reached around this time, when they had to build new aqueducts, so population probably increased from Early Augustan period) 275 AD: 600,000 (empire was already in economic and demographic decline during the crisis of the 3rd century, by this time most of the city was enclosed in the 1,373 hectares of the Aurelian walls). 800 AD: 25,000 (population collapse following the fall of the Western Roman Empire, Rome still remained the largest city in Western Europe, with about 20,000 to 30,000 inhabitants, as urban populations collapsed all over Western Eurasia).

The period of the Late Republic and Early Roman Empire, around the year 1 AD, represented a historical peak in economic prosperity for the Mediterranean world, and when people had extra money available, they consumed luxury goods. Importing exotic goods from distant places like India was a consequence of this prosperity. Consumption of goods from India was not exclusive to the elites: Roman soldiers in Britain consumed Indian pepper. Although it is true that trade with India was mainly restricted to high-value goods like pepper and not bulk commodities like wheat or bricks. Inside the Mediterranean, the physical scale of trade was much greater, as African bricks have been found on Roman buildings in Italy.