Norse Vanir sea-god; ruler of Nóatún ("Ship-Enclosure"); patron of seafaring, fishing, wind, prosperity. Father of Freyr and Freyja by his unnamed Vanir sister-wife in Vanaheim, where sibling-incest was permitted. Sent to Asgard as hostage after the Æsir-Vanir war alongside his children; counted among the Æsir for cult purposes while remaining Vanir-by-origin. Married Skaði (jǫtunn-daughter of Þjazi) by the foot-choosing weregild trick; the marriage failed when their incompatible domains (sea vs. mountain) made cohabitation unbearable. Per the Háleygjatal genealogy preserved by Snorri, fathered Sæmingr (founder of the Hákon-jarls' royal line at Hlaðir) by Skaði; the competing Ynglingatal tradition makes Sæmingr Óðinn's son. Per Vafþrúðnismál 39, will survive Ragnarǫk and return to Vanaheim. The Tacitus-attested 1st-c. CE Germanic Nerthus cult (Germania 40) is etymologically the feminine cognate of Njǫrðr (Proto-Germanic *Nerþuz); the millennium-long development from a Germanic earth-mother-goddess to a Norse sea-father-god is one of the most-debated cases in comparative Germanic religion. Per de Vries, Altgermanische Religionsgeschichte (rev. 1957); Simek, Dictionary of Northern Mythology (1993); Lindow, Norse Mythology (2001).