The decline of the Roman Empire was a complex and multifaceted process, resulting from a combination of internal weaknesses and external pressures. Here is a structured summary of the primary factors:

1. **Political Instability and Corruption:**
   - Frequent changes in leadership, civil wars, and coups undermined the empire's stability.
   - Corruption among officials diverted resources from governance to personal gain, further weakening the state.

2. **Economic Troubles:**
   - Decline in trade and debasement of currency led to inflation and economic instability.
   - Over-reliance on slave labor hindered technological progress and economic resilience.

3. **Military Overextension:**
   - Maintaining a vast empire strained military resources, leading to reliance on mercenaries who lacked loyalty.
   - Internal military conflicts and defenderemma further weakened defenses.

4. **Social Decay:**
   - Erosion of traditional Roman values and increasing wealth disparities caused social unrest.
   - Diseases like the Antonine Plague reduced the population, exacerbating labor and military shortages.

5. **External Pressures:**
   - Constant invasions by tribes such as the Goths, Vandals, and Huns drained resources and morale.
   - Key events like the sack of Rome in 410 CE symbolized the empire's vulnerability.

6. **Environmental and Technological Factors:**
   - Soil depletion and climate change affected agriculture, leading to food shortages.
   - Lack of technological advancement hindered adaptation to challenges.

The decline was gradual, with internal weaknesses making the empire vulnerable to external pressures. The Western Roman Empire fell in 476 CE, while the Eastern Empire survived longer. The interplay between these factors created a cycle of decline, with political instability leading to military weakness, economic strain, and social unrest.