They believed in Immorality to ensure the continuity of life after death people paid homeage to the gods both during and after their life on earth and they died they were mummified so the soul would return to the body giving it breath and life
Weather or not the emperor could become pope
The biggest city<span> in the </span>world<span> with 36.7 million inhabitants</span>
the answer to your question is a) they had advanced planning and developed effective military methods.