Factors contributing to the decline of the Roman Empire included political instability, economic troubles, military challenges, and social changes. Political infighting and corruption weakened central authority, leading to a series of short-lived emperors. Economically, heavy taxation, reliance on slave labor, and trade disruptions undermined agricultural productivity. Military challenges arose due to invasions by barbarian tribes, and the Empire's vast size made it difficult to defend effectively. Additionally, social changes and declining civic engagement diminished the sense of unity and loyalty among citizens. These combined factors contributed to the eventual fall of the Western Roman Empire in 476 CE.