heya, love the blog and you got me into history, so i wanted to ask you a question: rome unified most of europe and parts of asia and africa during the rupublic/empire. after the fall of Rome itself why didnt the italians reconciled their territory? why did the byzanthines and the lobards and venice didnt try to get their historical birthright?

Well, I think your question sort of answers itself. Italy wasn’t unified after the fall of the (Western) Roman Empire because there were multiple claimants to the territory. 

In the Gothic War alone, you had the Byzantines (backed up by Huns, Lombards, Slavs, and other foreign allies) against the Ostrogoths (who were in turn supported by the Franks, Burgundians, Alamanni). However, that statement makes things seem way more straightforward than they actually were, because those allies often became their own sides, as we see from the Franks, who turned on the Ostrogoths and almost succeeded in defeating both them and the Byzantines if it hadn’t been for a very timely outbreak of dysentery, and from the Lombards, who started out as Byzantine allies and ended up conquering most of Italy soon after Justinian’s death. 

And complicating the “historical birthright” narrative is the fact that the Ostrogoths were legally allies of the Empire, a lot of their leaders had received a Roman education and worked hand-in-hand with the Roman Senate, the surviving Roman bureaucracy, and the Catholic Church (despite the fact that they were personally Arians rather than Chalcedonians), so could arguably be considered to have as much of a claim to said birthright as the Greek-speaking, Orthodox Byzantine invaders. 

Why did soldier get paid in land rather than gold?

As I discuss here and here and here, paying soldiers in gold requires substantial state capacity – you need a large bureaucracy that can collect taxes in cash (which requires significant record-keeping, valuation, and enforcement capacities), you need the logistical ability to mint the necessary amount of coins and ship them to the army in time for pay day, you need both the authority/legitimacy and economic development to ensure that coin can exchanged with civilians for food and other supplies, and so forth.

Thus, even in the late Roman Empire, you see this system begin to break down – the commercial economy is weakening and urban centers are declining, which means the state is having a harder time extracting the necessary amounts of gold to pay the army (especitally when the army has gotten a sense of its political power and starts demanding more and more gold), the currency is becoming less valuable as a result, which means fewer people are willing to take coins (they’re not trading as much and now you see how all of these factors are mutually-reinforcing)

So the late Roman Empire begins to shift to a proto-feudal system. First they shift to a system of direct requisition of supplies from provinces by the army (which means the army is collecting the taxes itself so you don’t need a bureaucracy to do it for them) and taxes being paid in kind (which means that you don’t need to worry about currency as much). Second, from there it’s not much of a jump to just hand over land to armies in return for military service – whether you’re talking about the limitanei under Diocletian and Constantine or the stratiotika ktemata of the Byzantines, etc.

And in the West, once the Roman Empire falls completely, it was similarly an easy shift for ring-giving kings to start giving out land, now that the Roman bureaucracy and economy that let them get their hands on gold to turn into rings to hand out went away.