I am by no means an authority on the Roman Empire, but I can give this a stab.

The Empire's so-called "collapse" was a process that occurred between the third and eighth centuries (arguably); it wasn't instantaneous.

The years between 235-284 see a political succession crisis in which more than twenty different men claim and lose the title of Emperor while the Empire comes under attack by peripheral groups: "barbarians" from the north, past the Rhine and the Danube; and Persians, from the east.

The result is a growing need for individual provinces within the Empire to build up their armies, which means a slow shift of wealth and labor into areas where combat is occurring. Diocletian and Constantine oversee the end of these major conflicts, dividing the Empire into four parts that will later become two--a reform that is, according to Barbara Rosenwein, "a harbinger of things to come, when the eastern and western halves of the empire would go their separate ways." Constantine's reign marks a period of renewed political stability ("Late Antiquity"), during which significant changes in the cultural and spiritual life of the Empire occur: Constantine converts to Christianity, and later, Theodosius I's anti-pagan edicts (391 and 392), encourage conversion to Christianity, which becomes "the official religion of the Roman Empire." But, there is from the beginning considerable internal strife within church councils as they struggle to solidify a singular, precise doctrine, which really only creates dissent. Between the mid-fourth and -fifth centuries, we see evolving ideas of "rights" to the possession of holy relics, practices of worship, etc.

Then, the Sack of Rome by the Visigoths (410), "a stunning blow" to the Empire, is a result of the Black Sea Goths (one branch of a multiethnic, variously-nicknamed peripheral group) seeking more secure settlement within the Empire's borders after being pressured by invading Huns from west-central Asia in 376. They settle for a few years within the Empire, which half-heartedly welcomes the Goths and then leaves them in terrible socioeconomic conditions. The Goths rebel, carnage ensues, and eventually, they begin to settle more permanently within the provinces, since the Empire must either acquiesce or crumble. The result is that various "barbarian" groups become rooted and turn the Empire into a collage of nationalities and kingdoms.

Between the 4th-6th centuries, "barbarian" leaders are increasingly common throughout the various conquered provinces in the western half of the Empire. The 6th century also sees the outcome of excessive taxes that had been imposed on Romans since the 4th century: the slow fading of the urban middle class. People begin spreading out into the countrysides, where costs of living are less burdensome, as the rich upper class accrues power and "dominance" with land profits. In tandem, lifestyles and cultures are diversifying, especially in the east, which is in both respects "more akin to Persia than Gaul."

With conflicts boiling over between Rome and the Islamic world in the 7th and 8th centuries, these "territories that had for centuries been dominated by either Rome or Persia" now fight back--the Sasanid Empire of Persia conquers Egypt in the early 7th cent. while also crossing Byzantine borders, taking more and more territory until Rome's Eastern and Western halves are split down the middle. The mid-7th cent. also sees Islamic conquests near Arabia and in in the early 8th cent., in Spain--in a nutshell, by the beginning of the 8th century, the Roman Empire is the Byzantine Empire, its dispersal and fragmentation fueled by war and centuries-long periodic outbreaks of the Plague of Justinian.

This is a long-winded way of saying that the multi-faceted political, cultural, religious, economic, and social developments that led to the Roman Empire's "collapse" occurred over several centuries; they clearly had lasting effects on the lifestyles and cultures of the civilian populace, but they were nevertheless incremental, gradual changes that would not necessarily be perceived in a centuries-long scope from the vantage-point of an individual living in a fraction of the historical moment. One might also argue that the Empire didn't collapse, it simply shrank, diversified; the Byzantine Empire flourished for several centuries more before dissolving. These were changes that were occurring all across Europe, the Islamic world, and Asia, and maybe the historian's fallacy should be invoked if one assumes the average citizen perceived them singularly as "The Collapse of Rome."

Source: A Short History of the Middle Ages, Barbara Rosenwein (U Toronto Press, 2014) (primarily Chapters 1 & 2)

I am by no means an authority on the Roman Empire, but I can give this a stab.

The Empire's so-called "collapse" was a process that occurred between the third and eighth centuries (arguably); it wasn't instantaneous.

The years between 235-284 see a political succession crisis in which more than twenty different men claim and lose the title of Emperor while the Empire comes under attack by peripheral groups: "barbarians" from the north, past the Rhine and the Danube; and Persians, from the east.

The result is a growing need for individual provinces within the Empire to build up their armies, which means a slow shift of wealth and labor into areas where combat is occurring. Diocletian and Constantine oversee the end of these major conflicts, dividing the Empire into four parts that will later become two--a reform that is, according to Barbara Rosenwein, "a harbinger of things to come, when the eastern and western halves of the empire would go their separate ways." Constantine's reign marks a period of renewed political stability ("Late Antiquity"), during which significant changes in the cultural and spiritual life of the Empire occur: Constantine converts to Christianity, and later, Theodosius I's anti-pagan edicts (391 and 392), encourage conversion to Christianity, which becomes "the official religion of the Roman Empire." But, there is from the beginning considerable internal strife within church councils as they struggle to solidify a singular, precise doctrine, which really only creates dissent. Between the mid-fourth and -fifth centuries, we see evolving ideas of "rights" to the possession of holy relics, practices of worship, etc.

Then, the Sack of Rome by the Visigoths (410), "a stunning blow" to the Empire, is a result of the Black Sea Goths (one branch of a multiethnic, variously-nicknamed peripheral group) seeking more secure settlement within the Empire's borders after being pressured by invading Huns from west-central Asia in 376. They settle for a few years within the Empire, which half-heartedly welcomes the Goths and then leaves them in terrible socioeconomic conditions. The Goths rebel, carnage ensues, and eventually, they begin to settle more permanently within the provinces, since the Empire must either acquiesce or crumble. The result is that various "barbarian" groups become rooted and turn the Empire into a collage of nationalities and kingdoms.

Between the 4th-6th centuries, "barbarian" leaders are increasingly common throughout the various conquered provinces in the western half of the Empire. The 6th century also sees the outcome of excessive taxes that had been imposed on Romans since the 4th century: the slow fading of the urban middle class. People begin spreading out into the countrysides, where costs of living are less burdensome, as the rich upper class accrues power and "dominance" with land profits. In tandem, lifestyles and cultures are diversifying, especially in the east, which is in both respects "more akin to Persia than Gaul."

With conflicts boiling over between Rome and the Islamic world in the 7th and 8th centuries, these "territories that had for centuries been dominated by either Rome or Persia" now fight back--the Sasanid Empire of Persia conquers Egypt in the early 7th cent. while also crossing Byzantine borders, taking more and more territory until Rome's Eastern and Western halves are split down the middle. The mid-7th cent. also sees Islamic conquests near Arabia and in in the early 8th cent., in Spain--in a nutshell, by the beginning of the 8th century, the Roman Empire is the Byzantine Empire, its dispersal and fragmentation fueled by war and centuries-long periodic outbreaks of the Plague of Justinian.

This is a long-winded way of saying that the multi-faceted political, cultural, religious, economic, and social developments that led to the Roman Empire's "collapse" occurred over several centuries; they clearly had lasting effects on the lifestyles and cultures of the civilian populace, but they were nevertheless incremental, gradual changes that would not necessarily be perceived in a centuries-long scope from the vantage-point of an individual living in a fraction of the historical moment. One might also argue that the Empire didn't collapse, it simply shrank, diversified; the Byzantine Empire flourished for several centuries more before dissolving. These were changes that were occurring all across Europe, the Islamic world, and Asia, and maybe the historian's fallacy should be invoked if one assumes the average citizen perceived them singularly as "The Collapse of Rome."

Source: A Short History of the Middle Ages, Barbara Rosenwein (U Toronto Press, 2014) (primarily Chapters 1 & 2)

I am by no means an authority on the Roman Empire, but I can give this a stab.

The Empire's so-called "collapse" was a process that occurred between the third and eighth centuries (arguably); it wasn't instantaneous.

The years between 235-284 see a political succession crisis in which more than twenty different men claim and lose the title of Emperor while the Empire comes under attack by peripheral groups: "barbarians" from the north, past the Rhine and the Danube; and Persians, from the east.

The result is a growing need for individual provinces within the Empire to build up their armies, which means a slow shift of wealth and labor into areas where combat is occurring. Diocletian and Constantine oversee the end of these major conflicts, dividing the Empire into four parts that will later become two--a reform that is, according to Barbara Rosenwein, "a harbinger of things to come, when the eastern and western halves of the empire would go their separate ways." Constantine's reign marks a period of renewed political stability ("Late Antiquity"), during which significant changes in the cultural and spiritual life of the Empire occur: Constantine converts to Christianity, and later, Theodosius I's anti-pagan edicts (391 and 392), encourage conversion to Christianity, which becomes "the official religion of the Roman Empire." But, there is from the beginning considerable internal strife within church councils as they struggle to solidify a singular, precise doctrine, which really only creates dissent. Between the mid-fourth and -fifth centuries, we see evolving ideas of "rights" to the possession of holy relics, practices of worship, etc.

Then, the Sack of Rome by the Visigoths (410), "a stunning blow" to the Empire, is a result of the Black Sea Goths (one branch of a multiethnic, variously-nicknamed peripheral group) seeking more secure settlement within the Empire's borders after being pressured by invading Huns from west-central Asia in 376. They settle for a few years within the Empire, which half-heartedly welcomes the Goths and then leaves them in terrible socioeconomic conditions. The Goths rebel, carnage ensues, and eventually, they begin to settle more permanently within the provinces, since the Empire must either acquiesce or crumble. The result is that various "barbarian" groups become rooted and turn the Empire into a collage of nationalities and kingdoms.

Between the 4th-6th centuries, "barbarian" leaders are increasingly common throughout the various conquered provinces in the western half of the Empire. The 6th century also sees the outcome of excessive taxes that had been imposed on Romans since the 4th century: the slow fading of the urban middle class. People begin spreading out into the countrysides, where costs of living are less burdensome, as the rich upper class accrues power and "dominance" with land profits. In tandem, lifestyles and cultures are diversifying, especially in the east, which is in both respects "more akin to Persia than Gaul."

With conflicts boiling over between Rome and the Islamic world in the 7th and 8th centuries, these "territories that had for centuries been dominated by either Rome or Persia" now fight back--the Sasanid Empire of Persia conquers Egypt in the early 7th cent. while also crossing Byzantine borders, taking more and more territory until Rome's Eastern and Western halves are split down the middle. The mid-7th cent. also sees Islamic conquests near Arabia and in in the early 8th cent., in Spain--in a nutshell, by the beginning of the 8th century, the Roman Empire is the Byzantine Empire, its dispersal and fragmentation fueled by war and centuries-long periodic outbreaks of the Plague of Justinian.

This is a long-winded way of saying that the multi-faceted political, cultural, religious, economic, and social developments that led to the Roman Empire's "collapse" occurred over several centuries; they clearly had lasting effects on the lifestyles and cultures of the civilian populace, but they were nevertheless incremental, gradual changes that would not necessarily be perceived in a centuries-long scope from the vantage-point of an individual living in a fraction of the historical moment. One might also argue that the Empire didn't collapse, it simply shrank, diversified; the Byzantine Empire flourished for several centuries more before dissolving. These were changes that were occurring all across Europe, the Islamic world, and Asia, and maybe the historian's fallacy should be invoked if one assumes the average citizen perceived them singularly as "The Collapse of Rome."

Source: A Short History of the Middle Ages, Barbara Rosenwein (U Toronto Press, 2014) (primarily Chapters 1 & 2)