The Ennead (a word derived from Greek, meaning the nine) is a grouping of nine deities, most often used in the context of Egyptian mythology. As three of threes, the number was considered of great carnal power, and the groupings of nine Gods were considered very important.
There were multiple Enneads in ancient Egypt. Pyramid Texts mention the Great Ennead, the Lesser Ennead, the Dual Ennead, plural Enneads, and even the Seven Enneads. Some Pharaohs created Enneads that incorporated themselves; most notably, Seti I in his temple at Redesiyah worshipped the Ennead that combined six important deities with three deified forms of himself.
Interestingly, the Egyptian term pesedjet, usually translated as Ennead, does not necessarily mean a group of nine. There are some pesedjets that had a varying number of Gods throughout Egyptian history, and may have contained as few as seven, and as many as ten Gods.
The origins of this grouping are uncertain. The thinking up until mid-20th century was that it was created by Heliopolis priests in order to place their local sun-god Ra above all other deities such as Osiris; however many modern Egyptologists now doubt the theory. It is however almost a certainy that the Ennead first appeared during the decline of Ra's cult during the 6th dynasty, and due to it the cult soon saw a great resurgence.
Egyptian deities | Egyptian mythology
Ennead | Neunheit von Heliopolis (Ägyptische Mythologie) | Enneadi | Ennéade | Enneade | エジプト九柱の神々 | Eneada | Enneade | Enneada | Enéade | Эннеада | Enneaden | 九柱神