Egyptian civilization flourished along the Nile River from around 3000 BC to 30 BC. Key aspects included a centralized government led by a divine pharaoh; a society stratified into classes like nobles, peasants, and slaves; and a polytheistic religion centered around major gods like Ra, Osiris, and Horus. The Egyptians developed a hieroglyphic writing system, made advances in mathematics, astronomy, medicine, and engineering through structures like the pyramids, and had technologies including brick-making and glass-working.