The Anastasian reforms of the late 490s were essentially a massive monetarization of the Byzantine economy. Under Diocletian, many capitation taxes were assessed in kind; Anastasios switched over to currency entirely, and made it easier to do so by issuing a stable copper currency (the follis), which unlike the gold nomisma came in denominations small enough to use in everyday exchange. This was accompanied by adjustments to the taxation system itself that reduced the overall burden on the taxpayer and on merchants especially, a decrease that was easily made good by the apparently greater willingness of the taxpayers to pay in regular monetary installments as opposed to supplying grain or whatnot. The overall result of the adjustments to the Byzantine fisc was that, by Anastasios' death in 518 the empire had managed to amass a gold reserve of some 23M nomismata, which exceeded the total of the imperial budget over three years. This was accompanied by military reforms which saw an indirect increase in pay (leading to increased recruit quality) and an overall improvement in the training and size of the cavalry and horse-archer arms of service.uhh.. whoops. i didn't think this through. not conquering the western Europe would definitely make it very different, i don't know HOW different tho. i didnt know there was a reform in that time. perhaps there wasn't a reform ( unless the reform was directly in response to something that would have happened anyway). my knowledge on Byzantine history is certainty not complete.
The reforms were, in many ways, a long time in coming; certainly the Byzantines and Romans were substituting cash payments for payment in kind more and more frequently as the fifth century wore on; Anastasios standardized the whole thing, and married it to other fiscal and bureaucratic measures that overall simply increased government revenue. It's difficult to argue that the reforms wouldn't have happened eventually, since they were a natural extension of preexisting Roman government practice.
Perhaps the simplest way to ensure a Byzantine state that doesn't lose large swathes of territory to the Muslims is to fiddle with Maurikios and his campaigns against the Avars. Remove Phokas and ensure that Maurikios passes on the reins of power to a lawful heir, and Khusrau's invasion of a few years later, assuming it happens at all, has no opening. No need to mess with Justinian, much less with stuff that happened earlier.Mathalamus said:an unwritten rule that history stays the same unless otherwise specified. ( to prevent the history from being virtually unrecognizable, also my creativity is limited) the demise of Islam as a major factor HAD to have done some changes, i don't know what changes though. Islam still existed and it can still spread.
if you have suggestions i'm welcome to hear it.
On the whole, I disagree with the policy of 'having everything else happen unless something "big" directly interferes'. Simply put, there is an infinitesimal chance that even one child born after the PoD will begin as the same zygote it did in the original timeline, much less that all of them will be (tongue-in-cheek: what if Muhammad had been a girl?); there's also no accounting for the vagaries of war, plague, and even everyday life, in the course of which some people simply may not have survived to bear the children that they normally would have, or those children would have had vastly different experiences than they did in OTL. I recognize the desire to avoid undue work in creating the alternate world - it's just not what I would do if I were making a srs bzns althist.