Was he all conqueror? It is to my understanding he often left his conquered territories alone as long as they paid up.
He went from India to the border of China and backed away because the locals said there was a much bigger army on the other side and his men were bitching about the rain and wanted to go home. And yet even then on the way home he pushed into an area he had never been before. Did he just want to go on tour, in force?