How did the growth of territory help increase Roman trade

Answer 1

Essentially, trade within the frontiers of a territory controlled by a single government is safer and easier than trade in territories controlled by two or more governments. This is because moving valuable goods for trade, either across land (carts, pack horses, camels, etc...) or through bodies of water (by vessel), leaves a merchant potentially vulnerable to those who would like to steal the valuable goods in question. When a single government controls the territory through which a merchant transports his or her valuable goods, there is a higher likelihood of law and order being maintained, there is not ambiguity about who is in charge of upholding the law in the territory in question.

Moreover, trade within a territory controlled by a single government is usually less expensive because there is only one government to pay for the act of buying and selling goods. Buying and selling goods in more than one country / kingdom will mean that the merchant engaged in the buying and selling will have to pay two or more governments for the right to engage in trade in their territories.

If this is so, then why would merchants take the risk of engaging in trade in foreign countries / kingdoms? A key to making a profit is to offer for sale goods that are needed or wanted by people, but are scarce in a particular location. For example, if there was a need, a demand for iron in the city of Rome, but there isn't much iron ore contained in the mountains of Italy, then a merchant would have to go to where iron ore is more or less common, in, for instance, Gaul, purchase an amount to transport to from Gaul to Rome. Because iron ore is more common in Gaul, it is less expensive to purchase than in Rome. Because iron ore is less common in Rome, it can be sold in for Rome for more money than the merchant paid to purchase it in Gaul. In turn, a merchant would bring to Gaul goods that were common in Rome, but scarce in Gaul.

Under Julius Caesar, the Roman Republic conquered Gaul, bringing it under the control of the Roman Government. Before the Romans conquered the territory of Gaul, Gaul had no single government. It was ruled by a collection of mutually hostile Celtic tribes. It was far from safe to travel through different tribes' territories. Frontiers were in dispute, bands of warriors might be encountered who might take some or all of a traveling merchant's goods (along with killing the merchant), each tribal chief whose territory a merchant had to travel through would likely demand payment for safe passage, or might just seize the merchant's goods without compensation. All of these dangers and uncertainties were ended for merchants once the Romans established their control over all of Gaul.

Therefore, as the Romans extended their control over the territories surrounding the Mediterranean Sea and beyond, through a combination of conquest and diplomacy, it became safer, easier, and more profitable for merchants engage in trade. And, with trade made safer, easier, and more profitable, the amount of trade by merchants increased substantially.

Lastly, along with the relative safety provided by Roman troops stationed throughout the Empire and Roman warships patrolling the rivers and seas, the Roman practice of building a network of paved roads and bridges - built to facilitate the swift movement of Roman armies - made the overland transportation of goods by merchants far easier.