Deity of the planet Venus; an aspect of Inana/Ištar as Venus.
Ninsi'anna is the Sumerian deity of the planet Venus, venerated as morning and evening star. Originally female, she sometimes appears as male in later texts under the influence of Semitic theology where Venus deities were usually male (Heimpel 1982). Ninsi'anna is associated with illumination and radiance - both in some etymologies of his/her name, and in titles such as 'holy torch who fills the heavens' (ETCSL 220.127.116.11, line 4), and 'radiant god, whose light fills heaven and earth' (de Meyer 1982: 275).
Like other astral deities, Ninsi'anna is occasionally invoked in haruspicy. In a prayer from Old Babylonian Sippar, the diviner Ur-Utu asks the (male) god to 'be present in my offering, and place in it a portent of well-being and life' (de Meyer 1982: 274).
Ninsi'anna is linked to justice by Rim-Sin, who describes him as 'judge, supreme advisor, who distinguishes between truth and falsehood' (Frayne 1990: E18.104.22.168, translated there as if Ninsi'anna is female). The same inscription also credits Ninsi'anna with delivering the king's enemies into his hands - perhaps an indication of warlike qualities taken over from Inana/Ištar such as we see in the hymn for Iddin-Dagan (ETCSL 22.214.171.124).
Ninsi'anna's genealogy is unknown. Lambert (1966: 78) suggested that the obscure deity Kabta, with whom she is often paired in cylinder seal inscriptions, is her husband. However, Langdon (1914: 178) viewed Kabta as the goddess of the evening star, distinguished from Ninsi'anna as the deity of the morning star. This interpretation is supported by one instance where Ištar is said to be 'Kabta of the twilight' and Kabta 'goddess of the star', and perhaps also by certain cylinder seals which depict two goddesses flanking an inscription naming Ninsi'anna and Kabta.
Ninsi'anna was syncretised with Inana/Ištar probably by the end of the third millennium (an Amar-Suen inscription is addressed to dinana/ dnin-dsi4-an-na - Frayne 1997: E3/126.96.36.199), and certainly by the early second, where she appears in Inana/Ištar's circle in god lists. However, to some extent she retains a distinct identity - for instance, in Old Babylonian cultic texts she and Inana are listed separately (Richter 2004: 131-2, 371-2).
A temple to Ninsi'anna, é-eš-bar-zi-da, 'House of True Decisions', is described in a building inscription of Rim-Sin found at Ur, but it is not certain that the temple was located here (see George 1993, no. 261; Richter 2004: 477). Ninsi'anna also had temples in Sippar and Larsa and received cult at the Enmešara temple of Ninurta in Nippur (Richter 2004: 69-70). If dnin-dsi4-an-na refers to the same goddess, Amar-Suen and Šulgi both built temples for her, the former in Uruk, the location of the latter unknown (Frayne 1997: E3/188.8.131.52, E3/184.108.40.206).
Ninsi'anna is first attested (primarily as dnin-dsi4-an-na) during the Ur III period, where she received offerings at Nippur and Ur (Richter 2004: 31, 415), but most of our evidence for her/him comes from the Old Babylonian period. A hymn for Iddin-Dagan which celebrates the ruler's sacred marriage to Inana as Venus is labelled as 'a warrior-song of Ninsi'anna' (ETCSL 220.127.116.11). Here, Inana's martial and sexual characteristics are combined with the astral aspect represented by Ninsi'anna. As the evening star Inana rises 'like a warrior', prompting all living creatures to make obeisance to her (lines 89-100), and providing guidance for the traveller (line 139). After further praise and details of cultic performances in her honour, her amorous traits come to the fore as Inana beautifies herself and takes part in the sacred marriage with 'her beloved', Iddin-Dagan (lines 181-194). At the close, the hymn returns us to the astral plane with the image of Inana looking down joyfully from the heavens (line 223).
Outside the royal court, personal devotion to Ninsi'anna is in evidence from numerous cylinder seals, as well as in a letter to the (male) deity from a miserable worshipper who demands to know what he has done to deserve his current sufferings (Kraus 1971).
After the Old Babylonian period, Dilbat replaced Ninsi'anna as a name for Venus, and this is the regular term for the planet in astronomical tablets throughout the first millennium. However, Ninsi'anna survives as the name for Venus in Neo-Babylonian copies of the Venus Tablet of Ammiṣaduqa, based on Old Babylonian observations (Reiner and Pingree 1975), and is invoked as one of the 'gods of the night' in a Neo-Assyrian purification ritual (Reiner 1995: 67; note that the text translated here is a ritual edited by Langdon (1927: 74-7) and not, as Reiner states, the diviner's prayer edited by Oppenheim 1959, which mentions it as a comparandum).
In the latest dated attestation, Ninsi'anna, female once more, undergoes one final transformation. On a tablet from Seleucid Uruk she is equated with the goddess Antu, probably as part of the process whereby Antu was elevated above Inana/Ištar as the main female deity of the city (Beaulieu 1995: 201-2).
Ninsi'anna's iconography is unclear.
dnin-si-an-na means 'divine lady, illumination of heaven', which is of course appropriate for Venus as the morning or evening star. However, early spellings of Ninsi'anna's name, written with the sign si4 (= SU, 'to be red'), suggest that the original etymology may have been 'divine lady of the redness of heaven', referring not to the planet itself but to the colour of the morning and evening sky in which Venus is often visible (Heimpel 1982: 11).
Kathryn Stevens, 'Ninsi'anna (god/goddess)', Ancient Mesopotamian Gods and Goddesses, Oracc and the UK Higher Education Academy, 2016 [http://oracc.museum.upenn.edu/amgg/listofdeities/ninsianna/]