Why did they gradually begin loosing against barbarians...

Why did they gradually begin loosing against barbarians? Was there a degradation of Roman military tradition or did knowledge of how to fight effectively just gradually disseminate to the snow niggers like the Goths?

Rome or at least it's generals just began to rely on Barbarians partially to fill their own goals. Another factor would eventually be the growing Judeo-Christian presence in Rome and among its citizens. Worshippers of a man who preaches non-violence are less willing to take up arms then a man who worships Mars the God of war.

Christians have never had an issue when it came to picking up the sword.

Feel to blame this guy.

IIRC the Emperor needed to pay back a lot of generals so he made more coins by debasing the metal. Inflation set in. Military ties started to break and turn into less Imperial forms.
At the same time, instability in the East and North caused a mass migration of tribal peoples. They weren't too fond of the Roman border laws.
The Roman economy depended heavily on slave trade and labor, and many of the slaves were captured in wars. When the conquests slowed and stopped (thank the weakening military and barbarian expansion) the economy suffered. This worsened the crisis of Imperial power over the military. It became a positive feedback cycle.

Rome became the barbarians, the Greeks saved it from completely collapsing

I like this explanation more than simply the "lol, they gave germans swords" explanation.

The #1 problem predicating Rome's collapse was the lack of infrastructure in what is now France and Germany. Rome, like Greece, was built upon the Mediterranean Sea which allowed for quick and easy movement of soldiers and goods.

This was not the case to the north, as the rivers were not navigable and Rome was uninterested in building canals (such as the ones later generations would build right before the industrial revolution). In order to keep Roman rule secure local Governors and Generals were given a huge amount of power. Over time they not only came to use barbarian mercenaries (a thing otherwise frowned upon), but also the locals did not see themselves as "roman".

Decades of being ignored by Rome and Constantinople caused local people to support local families and barbarians rather than some far-off emperor. Rome never realized their mistake, in fact they accepted it when they split the empire between east and west. The latter quickly fell (as nobody trusted Rome itself) while the former kept going until Islam came about (but even then, one could argue that the Ottoman Empire was technically an extension of the Roman government but converted to a new sand religion).

Western Christians are not real Christians, they are pseudo-pagans.

Not him but it's such a broad issue it's very difficult to point to one specific issue. The Romans were not good at economic management and the collapse of the slave trade (causing inflation in the cost of labor eventually leading to emancipation) was a big (but not sole) reason the empire crumbled.

In the roughest sense possible it fell apart because the country was simply overextended. Not enough Romans, not enough slaves and not enough supply lines caused the basic logistics of the empire to break down. Eventually people came to stop trusting their old masters and revolted for home rule, which is what they got.

It gets even when you consider the quality of the troops deployed in the West. Before Constantine, the army had consisted of a mix of legionaries and auxiliaries equipped with chainmail and long thrusting spathas. The difference between the legionaries and the auxiliaries eventually became superficial, with auxiliaries being trained and equipped to the same standard as legionaries. After Caracalla granted citizenship to all freemen, the Roman army began to experience difficulties in recruiting. Military service was largely voluntary, and with the privileges the citizen legionaries enjoyed over the non-citizen auxiliaries now gone, it became less attractive to join the military.

The strategy of the Roman army, that of forward defence, had worked well in past centuries, but the lack of a strategic reserve (Something the Byzantines would rectify with the tagmata) meant that if an enemy force managed to defeat the army at the borders, they could enter the interior without much resistance. Constantine understood this, and adopted a policy of defence-in-depth. As a part of this though, he decided to reform the army. The Praetorian Guard was disbanded, but this was inevitable. The main change to the army was the division of the legions into three classes of troops. Diocletian had made the legions smaller, reducing them from 5,000 men to 1,000 and then grouping them into army corps. Constantine split the legions into limitanei (Frontier), comitatenses (Interior), and palatini (Palatine) legions. While the limitanei were initially no different than the comitatenses or the palatini, they eventually became part-time soldiers. They were equipped with swords and large shields, but by 363 had stopped wearing armour entirety. The vast majority of the troops available in the West at the time of the Germanic invasions were limitanei.

>immigrants stimulate women's primal instincts

They stimulate YOUR instincts, you fucking cuck

>Why did they gradually begin loosing against barbarians?
They didn't. Rome went on btfoing barbs till the very end. The issue was that, by virtue of pestilence and civil war, the empire found itself without manpower for both the army and the fields, so it was forced to let in germans to populate and cultivate the land along the borders and man the army.

There is a mountain range between Italy and Greece aswell, doesnt change the fact that both France and Greece are easily reached by sea.

Also it doesnt change the fact that we have major archeological evidence of Roman infrastructure projects above the alps. Some of the largest aqauducts in the world were built in france

The comitatenses continued the professionalism the old legions had been known for. They wore chainmail and scale armour, and some carried iron darts called plumbata. They were trained to a high standard, but resented being based in the interior. They seem to have been rare in the West, with 16,000 based in Gaul, 11,450 in Africa, and 3,400 in Britannia. That's a total of 30,850 legionaries for the entire of the West. The Eastern army, by contrast, had nearly 80,000 legionaries. The last class of troops were the palatini, the palace troops. They were equipped to the same standard as the comitatenses, and consisted mainly of veterans. A unit of 38,000 palatini was stationed in Italy to deter usurpers, and 16,000 were attached to the Army of Gaul. It's important to note how small the Army of Gaul was considering it was based on the Rhine. It consisted of 32,000 men in total, who were supposed to defend a population of over eight million people. The Army of Britannia, by contrast, consisted of 15,900 men in total, who were supposed to defend a population of one million people. Those troops would have been much better off in Gaul. Compared to Gaul, Britain was isolated, hard to defend, and economically backwards.

The palatini were supposed to act as a strategic reserve for the army, but the frequent civil wars meant they were rarely used as such. Alaric's invasion of the West forced Stilicho to withdraw troops from the Rhine to protect Italy. By 406, the Rhine was wholly undefended, allowing a coalition of Germanic tribes to invade Gaul and Hispania. With the limitanei withdrawn and the comitatenses stationed in Italy alongside the palatini, the West fell with remarkable speed. This, combined with Constantine III's revolt in 407, which led him to withdraw the Army of Britannia to Gaul, led to the loss of Britain. By 419, the Vandals had taken Africa.

Majorian came close to restoring the West. He successfully reconquered parts of Gaul and most of Hispania, and nearly reconquered Africa. Had he lived, he may have been able to retake Africa and restore the Rhine-Danube frontiers. His death led to a series of usurpers taking over Rome. The West de facto ended when Odacer took Italy, but de jure, it continued until the death of Julius Nepos in 480, the last de jure Roman emperor. The foederati were an unusual class of troops. Rome had always used foreigners as mercenaries, but never in such numbers. The Germanic tribes were offered land in return for their loyalty, but Rome did not always give it. The revolt of Odacer was caused by refusal of the Magister Militum Orestes to grant the foederati the land they had been promised. The quality of the foederati largely depended on their tribal leaders and the resources available. Noble foederati could be equipped as heavy infantry, with chainmail, swords, face masks, and large shields. Peasant foederati could be little more than fodder equipped with simple spears. The foederati seem to have supplied a significant amount of the Roman army's archers and cavalry. The Roman army did have its own archers and cavalry, but the foreign element never went away. The barbarisation theory of the collapse of the Roman army has some significance, but as long as the foederati were treated well and recieved their land, they generally remained loyal. Their quality wasn't always the best, but a significant amount of foederati served as limitanei, comitatenses, and palatini, and they remained professional fighting forces. Eventually, by the time of Justianian, the limitanei became little more than a militia. Justinian placed so little stock in their fighting abilities that he stopped paying 255,000 limitanei in order to support a force of 105,000 comitatenses and 45,000 palatini.

Gaul was still underpopulated for its size.