* Geographical advantages: The eastern Empire had a more defensible border, with natural barriers such as the Danube and the Bosphorus Strait. This made it more difficult for invaders to penetrate. Additionally, the eastern Empire was less vulnerable to attack from Germanic tribes, who were the primary threat to the western Empire.
* Economic strength: The eastern Empire was wealthier than the western Empire, due to its control of the more prosperous regions of the Mediterranean. This wealth allowed the eastern Empire to maintain a larger and better-equipped army and navy, as well as to fund other important projects, such as public works and fortifications.
* Political stability: The eastern Empire was more politically stable than the western Empire, due to its strong centralized government. The eastern emperors had more control over their territories and were able to maintain a more orderly succession. This stability allowed the eastern Empire to weather the storms of invasion and civil war that plagued the western Empire.
* Cultural unity: The eastern Empire had a more unified culture than the western Empire, due to the dominance of Greek culture and language. This cultural unity helped to create a sense of identity and purpose among the eastern Romans and made them more willing to fight for their Empire.
In contrast, the western Roman Empire was plagued by a number of problems that contributed to its decline and fall. These problems included:
* Political instability: The western Empire was plagued by a series of weak emperors and civil wars. This instability made it difficult for the Empire to defend itself against its enemies.
* Economic decline: The western Empire's economy was weakened by a number of factors, including inflation, taxation, and the loss of trade routes. This decline made it difficult for the Empire to maintain its army and navy.
* Barbarian invasions: The western Empire was constantly under attack from Germanic tribes, who eventually sacked Rome in 410 AD and 455 AD. These invasions further weakened the Empire and made it impossible for it to recover.