The Ancient Greeks worshipped many gods and goddesses. Many of the gods were part human, which meant they were not perfect! They were immortal, though, which means they would live forever. Ancient Greeks believed that the twelve most important gods lived on Mount Olympus.
Zeus was the wisest and most important of all the gods. He was God of the Earth and the Sky, and is often shown holding a bolt of lightning. The Ancient Greeks believed that Zeus threw bolts of lightning when he was angry, causing our thunderstorms.