| Transcript |
| · | Intro |
| 0:05 | · | I'm excited to announce our channel's first official merch! So you can now |
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| 0:29 | · | For most of the Western Roman Empire, the largest and most troublesome frontier was the one along |
| 0:34 | · | the Rhine and Danube rivers. The legions stationed along this over 2000 km long border were subject |
| 0:41 | · | to continuous incursions by Germanic tribes, who were responsible for some of the largest |
| 0:46 | · | military defeats that would lead to the ultimate demise of Rome. But despite these few failures, |
| 0:52 | · | in large part due to continuous internal civil wars, the Roman system of guarding |
| 0:57 | · | and maintaining this border was so ingenious, that it stood unshaken for centuries, always shifting, |
| 1:04 | · | adapting, and crushing incoming armies, while allowing its western provinces to |
| 1:09 | · | thrive in safety and peace... The Rhine and Danube rivers were highly effective natural defenses, |
| 1:16 | · | but they had a small weakness. In the area know as the Agri Decumates, both rivers are born and |
| 1:22 | · | flow differently, creating a small chink in the Roman defensive line, and a narrow gateway for |
| 1:28 | · | any invading army to comfortably march through, and be at the heart of Rome in a matter of days. |
| 1:34 | · | In this video, we decided to focus on THIS area, not only covering its evolution in |
| 1:40 | · | becoming one of the most complex and fascinating Roman frontier systems, |
| 1:44 | · | but also explaining how the Romans thought and approached the idea of frontier defense, |
| 1:49 | · | and of course, recreating parts of it in 3D... Without further ado, let's begin! |
| · | Creation of the Frontier |
| 1:55 | · | The Agri Decumates would grow to become a VERY formidable frontier, but surprisingly, |
| 2:01 | · | it was not a project of a single Emperor or military commander as one might assume. In fact, |
| 2:07 | · | it took decades for the whole area to be conquered through numerous short-term projects done by |
| 2:12 | · | different emperors, all aimed at solving specific smaller plans, rather than a single grand goal. |
| 2:14 | · | The region first entered the Imperial agenda in the aftermath of the Year of the Four Emperors |
| 2:19 | · | and the Batavian Revolt. These events outlined that although the Rhine frontier was strong, |
| 2:25 | · | it had many weaknesses which called for a new system to be put in place. The provinces |
| 2:30 | · | of Germania Superior and Raetia were, until this point, fairly isolated in guarding their sections |
| 2:36 | · | of the frontier, and the first upgrade Emperor Vespasian and his successors did was to construct |
| 2:42 | · | a road which connected the legionary bases of both provinces, together with the necessary forts |
| 2:48 | · | and other installations to keep this route secure. Each fort shown here had a garrison of two hundred |
| 2:54 | · | men at best, and operated as the headquarters for the several watchtowers and fortlets around |
| 3:00 | · | each one. The entire project would only be fully completed during the reign of Domitian |
| 3:05 | · | in the mid 80s AD, and would ensure the rapid mobilization and response time of troops between, |
| 3:12 | · | not only the two provinces, but the entire Rhine and Danube frontier systems... After the infamous |
| 3:18 | · | war against the Chatti in the mid 80s AD, Roman forces began securing large tracts of fertile |
| 3:24 | · | land to the north. To shield them from Germanic raids, a system of forts was built around them. |
| 3:31 | · | During the reign of Trajan, the first attempt to create a definitive frontier was made. With Rome's |
| 3:36 | · | forces tied up in the distant wars with Dacia and Parthia and new lands being incorporated into |
| 3:43 | · | the Empire, saving up precious manpower was the challenge. Weak points were reinforced with new |
| 3:49 | · | fortifications, and the gap between the Neckar and Main rivers was finally closed off. After |
| 3:55 | · | Trajan, Emperor Hadrian would add his own touch to the defenses by building a three meter tall timber |
| 4:02 | · | palisade that spanned hundreds of kilometers, thus clearly marking the border and limit of |
| 4:07 | · | the Roman Empire, at least only in Germania Superior (in the late 110s and early 120s). |
| 4:11 | · | It is only in 158, over 30 years later, under Antoninus Pius, would Raetia also |
| 4:17 | · | start constructing a palisade of its own. In an attempt to secure the more fertile |
| 4:22 | · | land east of the border, a new 80 kilometers long defensive line was built from scratch |
| 4:28 | · | following the same principles applied by Trajan and Hadrian. Antoninus' decision |
| 4:33 | · | must have caught many local commanders completely by surprise. At the fort of Elztal-Neckarburken, |
| 4:39 | · | for example, the local garrison had just finished constructing and renovating their bathhouse, |
| 4:44 | · | a very expensive and complicated building to construct, when they were ordered to demolish |
| 4:49 | · | everything and move 30 kilometers to the east, which historians have called the “outer |
| 4:53 | · | limes”. Regardless, all constructions were quickly finished by the year 165. |
| 5:01 | · | Under the reign of Marcus Aurelius, a few more forts were built, and the now decaying palisade |
| 5:07 | · | was in some places replaced by a 6 meter wide ditch and rampart or stone wall. Interestingly, |
| 5:13 | · | in Germania Superior the towers remain detached from the ditch or rampart, |
| 5:19 | · | but in Raetia, the stone wall was integrated into the towers. This |
| 5:23 | · | change could be seen right at the border between the two provinces, implying that |
| 5:28 | · | their governors were likely each responsible for the defensive constructions in their regions, |
| 5:34 | · | while still keeping everything cohesive and singular; once again, “organized chaos”... |
| · | The Roman thought process |
| 5:37 | · | The way everything organically progressed through the years once again onlines an |
| 5:41 | · | underlying theme that repeats itself in every video we make about the Romans, |
| 5:46 | · | and that is that they relied on a system of “organized chaos” in everything they did, |
| 5:52 | · | and this section of the frontier was no different. At first, parts of it may seem unnecessary, |
| 5:58 | · | redundant, or not fortified enough, and as if a straight consistent line of defenses would be |
| 6:03 | · | a better option. But upon closer inspection, one can slowly realize that is not the case, |
| 6:10 | · | and everything was impressively optimized for its purpose. The overextended forts in the north were |
| 6:18 | · | skillfully tailored to maximize every advantage of the terrain, and positioned along the highest |
| 6:23 | · | peaks of hills, being thus able to detect danger much further away than if they were |
| 6:29 | · | positioned along a straight. And forts like Saalburg protected vital passageways into the |
| 6:35 | · | region. Their extreme position also protected a sizable chunk of fertile land upon which several |
| 6:42 | · | military colonies and civilian settlements were created, to both act as a buffer zone and provide |
| 6:48 | · | the frontier with supplies and manpower... The lack of a palisade in some areas was only due |
| 6:55 | · | to the presence of a river, which served as a natural defense that disregarded the needs for |
| 7:00 | · | a palisade, as it would only take up unnecessary time and supplies to construct... The area in the |
| 7:02 | · | east might seem underdeveloped and weak, but that is only because the Romans paid careful attention |
| 7:08 | · | to local population densities, and tribes ahead of this area were less numerous and fairly unhostile, |
| 7:16 | · | allowing less men to safely garrison this area... Only when areas were flat or heavily forested |
| 7:23 | · | did the Romans create a straight line of defenses to use the least possible amount of materials and |
| 7:30 | · | manpower. THIS section was actually so perfect that it varied in straightness by only 1 meter |
| 7:36 | · | from start until end; quite impressive if you think about its length. Similarly, |
| 7:41 | · | by not just closing the gap between the Rhine and Danube, the Romans were able to cut the distance |
| 7:47 | · | of the entire frontier. This policy allowed the Romans to maximize their limited manpower |
| 7:56 | · | reserves to maximum effectiveness, thus being able to free up vital troops for unexpected campaigns... |
| 8:04 | · | [text for "Ope-era" sponsorship redacted] |
| · | The watchtowers |
| 9:18 | · | This 550 kilometer long frontier encompassed not only 60 forts, but also 90 fortlets, |
| 9:25 | · | and about 900 watchtowers, which were too small to be shown on this map. And all of |
| 9:31 | · | them were at some point expanded, downgraded, relocated, or simply abandoned to suit the |
| 9:36 | · | needs of emperors and local commanders alike. Maintenance was another reason |
| 9:41 | · | that buildings had to constantly be worked on. Wood was the primary material used, |
| 9:46 | · | but because it had a lifespan of only a few decades, soldiers would have been forced |
| 9:51 | · | to constantly replace decaying materials for new ones or move to new positions altogether... |
| 9:57 | · | Shown here is a reconstruction of one of the many watchtowers (Hesselbach-10/33) built by |
| 10:01 | · | Trajan and Hadrian (along the Odenwald Ridge), and our model belongs to the later stages of |
| 10:05 | · | occupation in the mid 140s, when due to the decaying of the wood, the tower was rebuilt |
| 10:11 | · | in stone and plastered in white, with a roof of oak shingles. It is a rather small construction, |
| 10:17 | · | and such watchtowers were built at every 500-600 meters along the palisade. The tower's entrance |
| 10:24 | · | was on the second floor and was only accessible by a ladder which could be pulled up and stored away |
| 10:30 | · | in case of an attack. A watchtower like this would only accommodate 4 to 8 men, who all served on the |
| 10:36 | · | second floor, while the ground floor acted as a storage facility. The protruding gallery granted |
| 10:42 | · | the soldiers a 360º view of the surrounding landscape, enough to spot any sizable force well |
| 10:48 | · | in advance and transmit a signal to neighboring outposts. As such, these structures had to be |
| 10:54 | · | clearly visible by other nearby positions in order to communicate effectively. We can assume that |
| 10:59 | · | watchtower garrisons were not meant to engage the enemy or intercept any incoming raids, but instead |
| 11:05 | · | to passively survey the countryside and report any suspicious activity. But this didn't mean |
| 11:10 | · | they were completely harmless. Remains of multiple missile weapons have been found in many of these |
| 11:16 | · | structures and suggest that at the very least they could offer a token resistance when needed. |
| · | The fortlets |
| 11:22 | · | Located about a kilometer behind the watchtowers would be fortlets, positioned between the key |
| 11:28 | · | forts. This here is the fortlet of Rötelsee (Römisches Kleinkastell Rötelsee), built |
| 11:32 | · | during the construction program of Antoninus Pius, near the modern town of Welzheim in |
| 11:37 | · | Germany. Situated on a small hill (east of the Limes Road), this fortlet was abnormally close |
| 11:42 | · | to the Limes palisade, being only 40 meters away from it. Fortlets like these were built |
| 11:48 | · | to defend strategic places and bridge the gaps between the larger forts and make it |
| 11:53 | · | harder for raiding parties to slip between them. These structures were also fairly small in size, |
| 11:59 | · | with this one measuring 18.5 meters on each side, and housing only a couple dozen men. |
| 12:06 | · | The fortlet itself had very limited defensive capabilities, with only a ditch, 2.5 meter high |
| 12:12 | · | walls, and no towers for protection. This fortlet was accessed from the western side, the one facing |
| 12:15 | · | the border; where the ditch was interrupted by three improvised earth bridges which could |
| 12:15 | · | be barricaded in case of an attack to create an additional defensive line. Over the ditch, |
| 12:16 | · | a small single gate granted access to the fort. Inside the fort was built a single |
| 12:18 | · | U shaped wooden structure that acted as the garrison's barracks, storage facilities and |
| 12:23 | · | command center. The inner courtyard also hosted a large fireplace where the garrison would cook |
| 12:29 | · | and eat their daily meals. On the south side, a small sewage canal was also present, that would |
| 12:35 | · | allow the disposal of any waste into the ditch outside. Even the smallest of Roman positions |
| 12:41 | · | had to stay neat and clean... Given the reduced size of the garrison, buildings like the praetorium or |
| 12:43 | · | principia are absent here, as all the members of the garrison would have been below the rank |
| 12:43 | · | of centurion and therefore not allowed the extra space enjoyed by their superior officers. In fact, |
| 12:44 | · | many of these positions were assigned temporary commanders from the immunes or principales, |
| 12:49 | · | the higher ranks of Roman legionaries. These, tasked as curatores would run the daily routines |
| 12:55 | · | and tasks in these fortlets, thus distributing orders from the main Legionary forts further back, |
| 13:01 | · | and creating a network from the largest forts to the smallest of watchtowers. After all, |
| 13:07 | · | the primary duty of these fortlets was the manning of local watchtowers, to which they rotated men on |
| 13:13 | · | the daily. They were also charged with traffic control of authorized crossings through the |
| 13:18 | · | frontier gates, the monitoring of activity beyond the frontier palisade and finally, |
| 13:23 | · | the interception and destruction of small raiding parties that managed to slip through. As you can |
| · | The Roman Grand Strategy |
| 13:29 | · | probably tell by now, Romans never thought of border defense as an impenetrable barrier. Even |
| 13:35 | · | the palisades were never really intended to prevent attacks, but rather to funnel |
| 13:39 | · | in public traffic through specific outposts in order to better control movement. After all, |
| 13:45 | · | a lot of trade and cultural influence occurred between the Germanic and Roman people, and through |
| 13:50 | · | the centuries, many along the border grew fairly reliant on each other. The same thought process |
| 13:56 | · | was applied to some degree in Rome's other borders too. In North Africa, some parts of |
| 14:01 | · | the border were particularly weak and overcrowded by trade, while Hadrian's wall in Britannia was |
| 14:07 | · | perhaps the closest to a solid border, though even it worked more like a funnel than an impenetrable |
| 14:13 | · | fortification, as any mid-sized attack could fairly easily breach it. Roman borders were |
| 14:19 | · | actually far more effective at slowing down attackers on their way BACK after raiding, because |
| 14:25 | · | even a thin wooden palisade or shallow trench is a tough obstacle when over encumbered with loot. |
| · | Fighting Invaders |
| 14:32 | · | But the vast majority of enemy incursions were fairly small, aimed at minor sabotage, |
| 14:37 | · | reconnaissance, or even stealing and smuggling for personal gain. Against these troublemakers, |
| 14:43 | · | the small watchtowers and fortlets, armed by only a few dozen men and supplemented by occasional |
| 14:49 | · | mounted patrols, were highly effective. And they were expected to track and catch them |
| 14:54 | · | if possible. A surviving letter from Roman patrols in Africa gives us a great example of this: “Fifty |
| 15:01 | · | (?)camels [having been stolen] by 18 barbarians (...) I have pursued [with?] three horsemen and |
| 15:06 | · | infantry (...) through impassable areas and we fought them (...) But, surprised during the |
| 15:11 | · | night (...), we retreated to the fortlet (...).” Regarding larger incursions, their role was |
| 15:16 | · | largely unknown. After raising the alarm and signaling nearby positions, they would probably |
| 15:22 | · | be expected to either fall back to regroup or barricade themselves in the forts to delay |
| 15:27 | · | the enemy, though we can't be sure. Another surviving letter speaks about this constant |
| 15:32 | · | uncertainty and fear that the watchmen would feel: “Bassus to Galates, his brother, many greetings. I |
| 15:39 | · | beg you, brother, give me news of yourself often, because you know that if there is trouble, I will |
| 15:44 | · | not just be worried about you. Indeed, I fear for myself, because we are not very many here.” |
| 15:50 | · | Surprise attacks, skirmishes and raids could turn a peaceful day at work into a fight for |
| 15:55 | · | survival and the risk of an inglorious death at the edge of the world. So most of the border |
| 16:01 | · | was garrisoned by non-Roman auxiliaries, with the large legionary fortresses being way in |
| 16:06 | · | the back. But containing their fear was not the only thing that watchmen would occupy themselves |
| · | Impressive self-sufficiency! |
| 16:11 | · | with. Many in the fortlets and watchtowers would engage in activities to self sustain themselves, |
| 16:17 | · | and sometimes even earn a side income. The frontier had a well coordinated logistical system, |
| 16:23 | · | but it was prone to interferences, delays, or outright disruptions that would put |
| 16:27 | · | strain on the soldiers along the border. A surviving letter gives a great example |
| 16:32 | · | of this: “. . .the 'acisculus' of the mill is broken – the iron part – and there is nothing |
| 16:37 | · | we can do . . . in the fortlet. I've dispatched Krinolaios, cavalryman of the turma of Satrius, |
| 16:43 | · | with the iron part in order for it to be repaired. That is why we ask you, Lord, |
| 16:47 | · | to return it at once. Indeed, we do not have the means to live if the mill is not restored.” |
| · | The frontier's death |
| 17:51 | · | Despite the ever increasing germanic activity and eventual breaches during the IIIrd century, |
| 17:56 | · | the frontier in the Agri Decumates continued to mark the edge of the Roman Empire through |
| 18:01 | · | the IIIrd century until its final abandonment in the late 250s and 260s AD. By this time, the |
| 18:07 | · | numerous crises engulfing the Empire, including the breakaway of a new Gallic Empire, meant that |
| 18:13 | · | the frontier simply had to be given up. The land would be instantly captured by the Alammani, who |
| 18:19 | · | would launch incursions through it for the next couple centuries. Today, thanks to the titanic |
| 18:26 | · | efforts of German archaeologists, historians and technicians, several places of the frontier have |
| 18:31 | · | been reconstructed and are accessible to the public as UNESCO World Heritage sites... |
| 18:37 | · | We hope you enjoyed visiting the upper Rhine Roman frontier! To see how it compares to |
| 18:42 | · | other Roman frontiers, in the north and east, check out our other videos here. And |
| 18:47 | · | consider supporting our team on Patreon! I hope to see you all in the next one! |
