Explain and analyse How and why ruler-cult develop in the Hellenistic World?

Explain How and why did ruler-cult develop in the Hellenistic World?

All sources are given and are separated into two categories: Ancient & Modern

Ancient:

https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Plutarch/Lives/Demetrius*.html

Modern:

Badian Deification (pg 244-281)

The Greek World (pg 153-175)

Koenen reading (pg 25-115)