More of a one-off thing, really! So, for those of you who don't have an encyclopedic map of the Roman world in your head at all times (for shame), [this is the area that we're talking about.](https://en.wikipedia.org/wiki/Nabataean_Kingdom#/media/File:Nabatean_Kingdom_(flat_map).svg) Now, you might be wondering, "what in the world was important about this tiny patch of land? Why didn't the Romans just conquer it, since it was right there? Why didn't the Romans take Arabia, since it was always known to be incredibly wealthy?"

Well, those are all fantastic questions. But let's start at the top and talk about Ancient Nabatea for a sec. The Kingdom was a peripheral one to the Roman Empire, and had thrived through the Ptolemaic rule in Egypt. Much of the dealings of the kingdom were centred around its capital city: Petra. Now, when I say that, you probably get an instant image of the famed Treasury, and for good reason - it's one of the most incredible extant structures in the region. There's more city than just the Treasury, of course, and the city itself was an invaluable one. It was a crossroads of sorts, connecting its port of Leuke Kome (more on this place later), which was a bustling trade hub, to Petra - which was another trade city, but built around an oasis - to the wider Greco-Roman world. Huge amounts of wealth flowed through, and the rulers of the city were more than happy to allow this to continue. The spice and aromatics trade were big money, after all, and the merchants who trafficked in them needed both an emporium and a place to stop on the trip to get water. Know what else merchants like? Safe roads! And the Nabatean Kingdom provided. Throughout the entire region, strict, extremely thorough, defenses against bandits were a must. Constant patrols rode out from the cities, mercenary bodyguards hung out there for hire, guardposts were established along the roads, and this advertising paid off. In the early years of the Roman Empire, Egypt had just come under Roman auspices and wasn't necessarily the safest place. Heck, the roads themselves were mediocre and potentially dangerous, and travel had to be conducted by night. Heaven forbid you arrive in the flood season, when the roads themselves were impassable. Nabatea offered a nice, constant solution, for the low, low price of some taxation.

They maintained a (relatively) friendly relationship with the powers that were in the region, whether it was the Ptolemies or the Romans themselves - in fact, they seemed to be rather delighted by the prospect of Roman domination, since, offering themselves as essentially a client state, they were able to get quite a few of the benefits of Roman centralization (both a higher number of consumers and more stable trade routes? Okay!) without having to pay the costs. And, as friends to the Roman people, they could even offer their...assistance, as it were.

We're gonna be continuing to look at the first few years of Augustus' consolidation. Egypt, by far the most valuable province, was under his control, with the Senate having "voted" to give it to him in perpetuity. He established that control rather quickly, and his first steps were to create and maintain a stable, efficient, bureaucracy. But he wasn't keen on spending time away from the centre of the empire - doing so would have been political suicide, considering he had destroyed Antony's personal credit for doing the same. So he appointed a prefect - not a governor or proconsul, but more akin to a manager (same thing, but the verbiage is important) - to Egypt. The first prefect's name was Cornelius Gallus, and it was a pretty significant honour. Augustus had him conduct honourary "spear wavings" at the Egyptian borders, letting the tribes beyond know that they definitely meant business, even if there also seemed to be extremely strict orders to Not Cross That Border By Any Means. Unfortunately, he let his mouth get ahead of him and talked about how he thought Augustus was getting too big for his britches, which caused a swift case of suicide to head his way.

Now the background's starting to end - because the next prefect was named Aelius Gallus (relationship unknown, but probably not close family). He doesn't seem to have been particularly keen to share the fate of his predecessor (suicide is bad for your health), and so, when Augustus sent him to Egypt with a set of orders, he just agreed that he could definitely accomplish said orders quickly and efficiently. Luckily, we have a written record from a man who was supposedly with the prefect at this time, who describes said command (Strabo 16.4.22):

Many of the special characteristics of Arabia have been disclosed by the recent expedition of the Romans against the Arabians, which was made in my own time under Aelius Gallus as commander. He was sent by Augustus Caesar to explore the tribes and the places, not only in Arabia, but also in Aethiopia, since Caesar saw that the Troglodyte country which adjoins Aegypt neighbours upon Arabia, and also that the Arabian Gulf, which separates the Arabians from the Troglodytes, is extremely narrow. Accordingly he conceived the purpose of winning the Arabians over to himself or of subjugating them. Another consideration was the report, which had prevailed from all time, that they were very wealthy, and that they sold aromatics and the most valuable stones for gold and silver, but never expended with outsiders any part of what they received in exchange; for he expected either to deal with wealthy friends or to master wealthy enemies. He was encouraged also by the expectation of assistance from the Nabataeans, since they were friendly and promised to co-operate with him in every way.

Augustus decided to send an army of 10,000 to...negotiate, having been told by the Nabateans that they would absolutely take care of all the things. That sounds like a fantastic time and definitely not like a repeat of the Athenian Sicilian Expedition, nope, not at all. The Nabatean Kingdom clearly had motive for this - remember, the vast majority of its wealth came from trade, and that trade often stemmed with...you guessed it...Arabia. India, too, but Arabia was huge. Now, Strabo likes blaming everything that went wrong on the guide that Gallus hired, who apparently was a devilish spy from the Arabians. That's not necessarily the case, since Gallus' actions seem to be of someone who's simultaneously trying to hurry and to be overcareful - remember, he was just appointed to this position and his predecessor had come down with a rough case of "being killed for not doing his job appropriately."

When Gallus arrived in the province, he immediately began his preparations. Strabo gives us some bits of it, but we have an even more valuable bit of information on this one! Egypt, being a desert, has a wonderful habit of preserving things - and, as luck would have it, one of those things happens to be a papyrus fragment from the beginning of this very expedition. Now, I'm pretty sure most of you reading this aren't necessarily fluent in Greek, much less papyrological reconstruction, so I'll give a quick TL;DR :) It says that (trans. Naphtali Lewis):

He forged a more than adequate quantity of weapons. He retrofitted Cleopatra's fleet, which had - understandably - been neglected after her death. He stationed garrisons at the entrances to the country. He prepared everything needed for war. Esteeming the Egyptians of the Thebaid to be better fighters than the others, he first encouraged them to volunteer for the expedition, but when they did not come forward, [he resorted to a draft(?)].

Now, if you're like me and think this is one of the coolest glimpses of the Roman preparations for war, I totally agree - because as soon as he made it to Egypt, he had the forges of the country working overtime to outfit his new army. The new army included auxiliaries from Judea and Nabatea, a large number of Egyptians, and perhaps a few cohorts from the two legions that were stationed in Egypt. The legions were also commanded to lock down the borders and ensure that peace was kept by any means in Alexandria (which was notorious for riots). But then there's an interesting tidbit also - retrofitting the fleet left by Cleopatra.