What caused Alexander the great his downfall?

Answer 1

There is a lot of speculation that Alexander died of poisoning from his own men, namely those who followed Cassander. Cassander, along with other Macedonians, Greeks resented Alexander for trying to incorporate those he conquered into his army, including marrying them off to "Asian" "Bactrian" or any other non-Greek woman.

Alexander himself married Roxanne, a Bactrian, which angered his close companions and army. However it seems that malaria is more than likely the culprit, after having contracted it while he was in India before heading back to Babylon where he died not long after. All the symptoms described in the history books suggest malaria.

If you can get past the camp and melodrama of the movie Alexander the story line shows that Alexander becomes increasingly "oriental" as in "Asian" (in the ancient world sense) as he travels with his army across the known world and incorporates those he conquers into his traveling army.

Answer 2

his death