The sun god of Annu (Heliopolis, near modern-day Cairo), he became a state deity in the Fifth Dynasty. Some traditions made him the creator of men, and the Egyptians called themselves "the cattle of Re".
His name is thought to mean "creative power", and as a proper name "Creator". Very early in Egyptian history, Re was identified with Horus, who as a falcon-god represented the loftiness of the skies. He was represented as a hawk-headed man or as a hawk. A combination of the two, Ra-Hoor-Khuit, "Re, who is Horus of the Horizons" showed the two as manifestations of the singular Solar Force.
Seeing as that the sun was a fire, the Egyptians believed that in order to travel through the waters of heaven and the underworld, one required a boat and so Re traveled in one. In the day, the boat was a great galley known as "Madjet" ("becoming strong") that rose in the east from behind "Manu" the mountain of sunrise and passed between two sycamores. As the sun set the boat Re used was a small barge called "Semektet" ("becoming weak").
The course that the boat took was determined by the goddess Ma'at. During his travels he had plenty of company. Several gods took the journey with him and their job was to help navigate the boat and thus make it's passage successful. Thoth and Ma'at stood on either side of Horus, who steered the boat and was also apparently the captain of the ship. In front of the boat swam two pilot fishes known as "Abtu" and "Ant". Other passengers include: Geb, Hu, Sia (intelligence) and Hike (magic). At night the god Upuaut (the Opener of Ways) stood a the prow.
The journey was not an easy one though. Monsters would constantly try to stop the boat. Among these were Sebau, Nak, and Apep. Apep was the most powerful of these. He was a personification of darkness and Re had to fight him successfully every morning before he could rise from the east. Apep was pictured as a serpent or as a crocodile. Alternately, either Thoth or Seth defended the barque against him. When Apep was successful, stormy weather would ensue. A solar eclipse occurred when Apep actually swallowed the barque. There was a book written about Apep called The Book of Overthrowing Apep which gives spells and information on how to defeat him. These spells were recited daily in the temple of Amon-Re in Thebes.
In later periods when Isis and Osiris overtook him in popularity, he remained "Re retjer-aa neb-pet" ("Re, the great God, Lord of Heaven") whether worshipped in his own right or later on, as half the Lord of the Universe, Amon-Re.