My question - which apparently turned into a micro-essay - is aimed at a more root cause investigation of the eternal favourite and discussed topic of why the Romans failed to conquer "Germania" when so few other areas posed an obstacle at the peak of its might.
TL;DR: Why did Rome really not conquer Germania when the reasons so often given seem to apply to other conquered areas as well?
See for example Why were the Romans unable to conquer Germania?
My interest was rekindled by the findings at Battle at the Harzhorn which wasn't just surprisingly far east into Germania but also at a rather late date (just before the onset of the Crisis of the Third Century).
I'm interested in a comparative analysis that, for instance, compares Gallia, Germania, Dacia, Britannia - and even Judaea if needs be - in terms of geography, climate, population (density and urbanisation).
- Inclemental weather (mentioned also by Tacitus): that applies no less to Britain or Friesia
- Dense forests: did Dacia or Britain have fewer forests? Lower Saxony has been mostly plains, moors and meadows for millenia, IIRC, likely no worse than Britain or "northern Gaul", i.e. what's now the Netherlands and Belgium
- Urbanisation: do we have any better comparison regarding the tribal and urban structure of Germanic vs Celtic tribes than going by Tacitus? Did even the British Celts all live in in nice central and targetable cities? From reading Caesar, I just about recall only Gergovia and Alesia in Gaul
- Wine: this has been mentioned semi-jokingly (and quoted in the other Stack), but here too, if "capability for viticultue" was a criterion, no Roman would have bothered with Britain (disregarding that thanks to AGW we may be talking about British Pinot Noirs in a few years ;) )
Having been challenged on this, I'll quote from the Oxford Companion to Wine, entry England
Seeds have been found at Roman site in Lond, Bermondsey, Silchester in Hampshire, and Gloucester, and stalks at a Roman villa near Boxmoore in Hertfordshire, but all without any evidence of cultivation [emphasis mine], so these may be the remains of imported raisins. And even if grapes were grown in England, we cannot prove that they were made into wine [emphasis mine]. Wine was certainly imported from Italy even before the Roman invasion. [...] Recent finds show that amphorae were produced at Brockley Hill, Middlesex [...] and also at London sites [...] They are of a type that according to archaeological evidence [...] were used as container for locally produced wine; the London amphorae were probably the work of immigrant potters from France. The amphorae all date from 70-100 AD: [emphasis mine] perhaps this short period could be explained by the edict issued by the Roman emperor Domitian, which , by reducing the number of vineyards in the provinces, put a stop to the Romano-British wine industry. [...] Our earliest conclusive evidence for wine-growing in Britain, then, must be Bede's Ecclestical History, which he finished in 731 [emphasis mine]. [...] 'Britain', he says, 'is rich in grain and timer; [...] and wines are cultivated in various localities' (Book I, ch. I). Unfortunately that is all he tells us about Anglo-Saxon viticulture, and what other information we have is scanty.
So, very little actual evidence of wine-making in Britain during the Roman Empire and what little we have points to a very short abortive period. And no indication of just what wines were grown. However, indeed, wines grown in Britain around the 11th to 13th century were actually praised. A bit after the Romans though.
- Resources: Britain had tin (and silver?), Dacia had gold, so understandable drivers. I've personally idly wondered if getting access to the vast stores of easily mineable brown/lignite coal in Germany could have triggered an earlier industrial revolution. Pure speculation, I know. Germania had (and has) very little beyond salt, iron and coal (and a number or ores that would have had little use in antiquity, such as uranium or tungsten)
- Defensibility: the Rhine (and Danube) as a natural barrier is often mentioned, however if we speculatively look at a map or Europe, for one a border along the Elbe, Oder or even Vistula would have shortened the length of a defensible border by the length of eastward shift along the Danube. In addition, those tribes who later conglomerated and, having learned from the Romans, became successful adversaries, would have been conquered provincials. Whether that would have helped against the Gothic, Hunnic or various *ar "wandering nations" is another issue, especially as Rome was wracked in civil wars
- Warfare: unless we assume the truth of some drivel about "Germanic superiority blablabla", I can't see any reason that the Roman approach to solitudinem faciunt, pacem appellant (they make a desert, and call it peace as Tacitus supposedly quotes an enemy chieftain) wouldn't have worked. Gaul wasn't just conquered but depopulated (if the Wiki article mentioned 3 million dead during Caesar's campaigns is true, that amounts to genocide by the presumed population density at the time. The death toll during the Jewish Wars was also horrendous, if going by Josephus, and must have left areas void of people). If they couldn't conquer them, Rome could have wiped them out, through force or by destroying crops and fields until famine took care of it.
Is this a case of "other areas had one or more of the obstacles, but Germania had all of them and even more so"?