Athtar is depicted in the Ras Shamra text of Canaan. He attempted to act as a substitute for Ba’al, but when he was unsuccessful, he descended to become the lord of the underworld instead. He is known as the chief divinity of the Minaeans, so perhaps his descent into the underworld indicates hostilities between the Canaanites and Minaeans. Athtar, apparently from the word athara, "to be fertile, to irrigate," would be an appropriate name for an underworld god, but is only considered a minor vegetation deity.
"Thereupon Athtar the Fierce
Goes up to the crags of Saphon;
He takes is seat on the throne of Ba'al the Mighty.
His feet do not reach the footstool,
His head does not reach the top thereof.
Then Athtar the Fierce declares, '
I may not be king on the crags of Saphon'.
Athtar the Fierce comes down,
Down from the throne of Ba'al the Mighty,
And he becomes King over the whole vast underground."
- Ras Shamra texts
The Sabeans of Sheba also recognize Athtar, for them however, he is superseded by Almaqah, the planet Venus and therefore is identical with Astarte. On the Shabwat inscription Athtar is the father of Sin, a Sabean moon-god. These two deities also appear as nearly related in the Babylonian legend of Ishtar’s descent to the Underworld, where Ishtar is regarded as the daughter of the god Sin. The mother of Athtar on another inscription is probably the sun.
In Arabia, Athtar was another name for Astarte or Ishtar. Divided into a male and female deity, (s)he was considered the mother and father of mankind. In this instance, Athtar was the name given to the male half. From pre-Islamic southern Arabia, his worship spread to Abyssinia, where he was known as Astar. Other possibly connected deities include Athar a(sh)-Shariq, Athtar Dhu Qabdim, Athtar Shariq, Athtar Shariqan, Athtar Sharqan, and Attr.