Which factor played the biggest part in downfall?

The biggest factor in the downfall of many historical empires and organizations is often attributed to internal strife, including political corruption, economic instability, and social unrest. These internal issues can undermine unity and weaken leadership, making it difficult to respond effectively to external threats. Additionally, failure to adapt to changing circumstances, such as technological advancements or shifts in public sentiment, can further accelerate decline. Ultimately, the combination of these factors often leads to a loss of power and influence.