What were the two main reasons for the decline of the byzantine empire?

1) civil wars

2) conversion to christianity

3) invasions

4) plagues

5) riots at the hippodrome

The two main reasons are 1 and 2

3, many invasions from the Ottoman Turks resulted in the rapid decline of the Byzantine empire, 450 AD to 1454 AD

4 Many plagues, brought over from the Turks erupted in citys like Athens and Constantinople, killing a good chunk of the Empire's population