How did Roman expansion compare to that of the Assyrians, Han Dynasty, and New Kingdom Egypt?

When comparing the expansions of Rome, Assyria, the Han Dynasty, and the New Kingdom, you will find that each civilization will have its own unique history. Generally speaking, in all cases, expansion will be achieved primarily through war and military conquest, but ultimately, the deeper you look into these comparative histories, the more you will find that the divergences between these different historical contexts tend to exceed any general similarities.

One element that immediately stands out is the degree to which, relative to the other civilizations in this comparison, Rome tends to appear relatively young from a cultural perspective. Rome had its origins as an Italian city-state, with its founding generally assigned to around 750 BCE (though this is an approximation, and much of its early history has been mythologized). Over the centuries, it gradually consolidated power through various campaigns against its Italian neighbors, gaining hegemony within Italy, after which point it began to expand outwards into the larger Mediterranean world. (The key moment in this transition can be found with the Punic Wars against Carthage, the first of which began in 264 BCE.)

In contrast, both the Han Dynasty and the New Kingdom built heavily off of various preceding dynasties stretching further into the past. In the case of the New Kingdom, it was founded by Ahmose I, who reunited Egypt after the second intermediary period. From there, you can delve further back in time toward the Middle Kingdom and further still into the Old Kingdom. This is not to say, of course, that the various periods within Egyptian History were perfect equivalents to one another, but there remains a certain sense of progression across the various Egyptian dynasties.

A similar quality can be observed with the Han, who were immediately preceded by the Qin Dynasty, who had previously unified China, bringing an end to the Warring States Period of the late Zhou. From there, you can look further back toward the Zhou Dynasty and the Shang Dynasty.

Generally speaking, there are points of comparison you can make between specific empires. For one thing, both Rome (especially as it expanded beyond Italy) and the Han were contemporaneous with one another, even as the Assyrians and the New Kingdom were both more ancient by comparison. On the other hand, you might draw a comparison between Rome and Egypt: while Egypt had been historically tied together by control of the Nile River, Rome tended to rely on the Mediterranean Sea to tie together its core provinces in a much similar manner.

The Assyrians, by contrast, were based much further inland in Northern Mesopotamia, with their power expanding across Mesopotamia and into Anatolia and Egypt. Meanwhile, the Han expanded upon the earlier boundaries held by the Qin Dynasty, making significant territorial conquests along its southern border. It would also conquer part of Korea and extend its power further west into Central Asia.

Generally speaking, the deeper you look into the histories of these various civilizations, the more complicated your comparisons will become.

What factors led to the expansion of Roman imperialism and how does it compare to the Assyrians, Han Dynasty, and New Kingdom Egypt?

Why was the empire of ancient Rome much more lasting than those of other empires? The genius of Caesar and Rome's military prowess springs to mind. But Rome's greatness stemmed from much more than its battlefield conquests.

Rome's system of roads was magnificent. Although the Romans were not the first ancient people to build roads, their roads were the most durable and the best. Road building went on for eight centuries, and the roads united distant corners of a far-flung empire. The Appian Way, which is still visible, was the earliest and most famous Roman road. Roads were also maintained by competent government officials. The roads were useful for military and economic purposes, and for the use of civilians. The construction of roads provided employment for soldiers between wars. Other empires, such as that of the Incas, had good road systems, but Rome's was nonpareil.

The Romans' penchant for organization and planning was also evident in its engineering and architecture. Sturdy bridges complemented the road system. Few ancient cities were as well-planned as those of the Romans.

Rome was also fortunate at key moments in its history. Rome could have easily lost the Second Punic War. Had Rome lost that key conflict, Carthage might have begun its ascent to world dominance.

Rome had a system of law based on the Twelve Tables (451–449 BC). These laws were later amended, but Rome's respect for its written laws made it a more powerful empire.

Finally, Rome's first emperor, Augustus, was a very capable ruler. He was the heir to the assassinated Caesar. After Caesar's death, years of civil war followed. Augustus led Rome out of that turbulent period and started the Pax Romana.

The continuance and expansion of Roman imperialism began around 260 B.C. with their first war against their main rival and neighbor Carthage, which was seen as a powerful threat due to their domination of trade in the Mediterranean Sea. To trade in the Mediterranean as well, the Romans defeated Carthage after more than 100 years of war called the Punic Wars, ending in 146 B.C. With that victory, the Romans became the most powerful Mediterranean state, starting their expansion.

The Romans also had superior military tactics, which contributed to their European domination. They knew that the further they expanded, the more wealthy Rome could be. Thus, Rome utilized military tactics such as the Phalanx (borrowed from the Greeks), the most advanced equipment at the time, and superior training. Roman military culture was focused on war, even in times of peace, with soldiers often training in one-on-one combat daily when not at war.

Conquering new lands raises the possibility of uprisings and conflict with the native people, but Rome was different. The conquered lands often benefited from Roman rule as they introduced new technology to improve ways of life, such as baths, roads, and improved housing.

This can be juxtaposed against other empires such as the Chinese Han Dynasty, as it was wrought with political turmoil, unsuccessful policies such as the privatization of private industries that would last only a decade, and civil wars.

Great concentrations of wealth in a city like Rome made it the target of envy and aggression from regional rivals, neighboring cities, and other great powers. Rome was initially a small village under the political domination of its Etruscan neighbors to the north in Tuscany. As Rome grew in wealth and power, its first wars were wars of independence.

In order to expand a defensive periphery around Rome and to eliminate strategic rivals, Rome began to fight, conquer, and assimilate these local and regional rivals. Eventually, successful warfare became one of the surest means of advancement for Roman aristocrats who were careful early on to frame their wars as "just wars" in the interest of the Roman equivalent of national security.

Life under Roman rule often brought greater peace and prosperity to newly conquered regions and their peoples, many of whom were eventually incorporated into the Empire as full citizens. Of course, Rome did have to worry constantly about German barbarians to the north, the Carthaginians to the south, and Huns and Persians to the east, so the empire provided a large buffer area behind which the city of Rome could stay relatively safe for many centuries.

Certainly let us not forget the role of Roman administration bureaucracy. The Roman system of administration and roads made holding together an ever-increasing series of lands achievable, and it also meant that troops could be mobilised quickly in order to counter threats and to invade new territories. So many of the original Roman roads are actually used as the basis for roads today in various parts of Europe.

One thing that caused Rome to expand continuously was political pressure.  Rome had a strong army, one which played a major role in the politics of the empire.  To keep the army happy, it was a good idea for Rome to fight wars that would bring riches to the leaders of the army.  The wars would also satisfy those leaders' desire for glory.  So, in a sense, the taking of empire led to the taking of more empire because the army that was needed to take the original empire wanted to keep taking more.