He became emperor upon defeating his older half-brother PERSON@1 in a civil war sparked by the death of their father , PERSON@2 , from an infectious disease thought to be smallpox .

He became emperor after defeating his younger half-brother PERSON@1 in a civil war that followed the death of their father , PERSON@2 , from an infectious disease -LRB- maybe malaria or smallpox -RRB- .
