In Egyptian mythology, Thoth (also spelt Thot), pronounced “tot”, is the Greek name given to Djehuty (also spelt Tahuti, Tehuti, Zehuti, Techu, Tetu) – the original pronunciation of his name is disputed, and may have been approximately Tee-HOW-ti -, who was originally the deification of the moon in the Ogdoad belief system.
Initially, in that system, the moon had been seen to be the eye of Horus, the sky god, which had been semi-blinded (thus darker) in a fight against Set, the other eye being the sun. However, over time it began to be considered separately, becoming a lunar deity in its own right, and was said to have been another son of Ra. As the crescent moon strongly resembles the curved beak of the ibis, this separate deity was named Djehuty (i.e. Thoth), meaning ibis.
The Moon not only provides light at night, allowing the time to still be measured without the sun, but its phases and prominence gave it a significant importance in early astrology/astronomy. The cycles of the moon also organized much of Egyptian society’s civil, and religious, rituals, and events. Consequently, Thoth gradually became seen as a god of wisdom, magic, and the measurement, and regulation, of events, and of time. He was thus said to be the secretary and counsellor of Ra, and with MaĆ t (truth/order) stood next to Ra on the nightly voyage across the sky, Ra being a sun god.
Thoth became credited by the ancient Egyptians as the inventor of writing, and was also considered to have been the scribe of the underworld, and the moon became occasionally considered a separate entity, now that Thoth had less association with it, and more with wisdom. Also, he became credited as the inventor of the 365-day (rather than 360-day) calendar, it being said that he had won the extra 5 days by gambling with the moon, known as Iabet, in a game of dice, for 1/72nd of its light (5 = 360/72).
When the Ennead and Ogdoad systems started to merge, one result was that, for a time, Horus was considered a sibling of Isis, Osiris, Set, and Nephthys, and so it was said that Hathor/Nuit had been cursed against having children during the (360) day year, but was able to have these five over the 5 extra days won by Thoth.
In art, Thoth was usually depicted with the head of an ibis, deriving from his name, and the curve of the ibis’ beak, which resembles the crescent moon. Sometimes, he was depicted as a baboon holding up a crescent moon, as the baboon was seen as a nocturnal, and intelligent, creature. The association with baboons lead to him occasionally being said to be dating Astennu, one of the (male) baboons at the place of judgement in the underworld, and on other occasions, Astennu was said to be Thoth himself.
During the late period of Egyptian history a cult of Thoth gained prominence, due to its main centre, Khnum (Hermopolis Magna), also becoming the capital, and millions of dead ibis were mummified and buried in his honour. The rise of his cult also lead to his cult seeking to adjust mythology to give Thoth a greater role, including varying the Ogdoad cosmogony myth so that it is Thoth who gives birth to Ra/Atum/Nefertem/Khepri, as a result of laying, as an ibis, an egg containing him. Later it was said that this was done in the form of a goose – literally as a goose laying a golden egg.
Thoth was inserted in many tales as the wise counsel and persuader, and his association with learning, and measurement, lead him to be connected with Seshat, the earlier deification of wisdom, who became said to be his daughter, or variably his wife. Thoth’s qualities also lead to him being identified by the Greeks with their closest matching god – Hermes, with whom Thoth was eventually combined, as Hermes Trismegistus, also leading to the Greeks naming Thoth’s cult centre as Hermopolis, meaning city of Hermes.
There is also an Egyptian pharaoh of the Sixteenth dynasty of Egypt named Djehuty (Thoth) after him, and who reigned for three years.