Short answers, pulled from the story.
The first known written record of polytheism dates back to the Sumerian civilization in Mesopotamia. Scribes carved cuneiform tablets describing a complex pantheon of gods who controlled the forces of nature and human destiny.
The Jewish writer Philo of Alexandria coined the term polytheism to argue with the Greeks. The word comes from the Greek words for many and god and has been used in various ways throughout history.
The Greeks created the Twelve Olympians, a group of powerful deities who ruled from Mount Olympus and intervened in human affairs. They later adopted and adapted many ideas from earlier belief systems like those of the Egyptians and Sumerians.
Hinduism presents a unique challenge to the classification of polytheism because it contains elements of monotheism, pantheism, and panentheism. The Hindu concept of Brahman is seen as the source of all existence yet is expressed through the innumerable deities that represent different aspects of the divine.
The majority of so-called folk religions in the world today are found in the Asia-Pacific region. These religions are often closely tied to the land and the natural world, with deities representing different aspects of nature and human experience.
The Roman Empire eventually adopted Christianity as its state religion, leading to the persecution of pagans and the destruction of many temples and sacred sites. However, polytheism survived in various forms, from folk religions to modern neopagan movements.