Name of the progenitor of the Yngling lineage, a legendary dynasty of Swedish kings from whom the earliest historical Norwegian kings in turn claimed to be descended. Information on Yngvi varies in different traditions as follows:
- Yngvi is a name of the god Freyr, perhaps intended as Freyr's true name while Freyr 'Lord' is his common title. In Snorri Sturluson's Heimskringla Yngvi-Freyr is euhemerized as a king of Sweden who reigned in succession to his father Njord who in turn succeeded Odin. His descendants are the Ynglings.
- In the Islendíngabók Yngvi Tyrkja konungr 'Yngvi king of Turkey' appears as father of Njord who in turn is the father of Yngvi-Freyr the ancestor of the Ynglings.
- In the introduction to Snorri Sturluson's Edda Snorri claims again that Odin reigned in Sweden and relates: "Odin had with him one of his sons called Yngvi, who was king in Sweden after him; and those houses come from him that are named Ynglings". Snorri here makes no connection between Yngvi and Freyr.
- In the Skáldskaparmal section of Snorri Sturluson's Edda Snorri introduces Hálfdan the Old, otherwise unknown, who is the father of nine sons whose names are all words meaning 'king' or 'lord' in Old Norse and nine other sons who are the forefathers of various royal dynasties, including "Yngvi, from whom the Ynglings are descended". But rather oddly Snorri immediately follows this with information on what should be four other personages who were not sons of Hálfdan but who fathered dynasties, but names the first of these as "Yngvi, from whom the Ynglings are descended".
(The Ynglingatal section of Snorri Sturluson
also introduces a second Yngvi son of Alric who is a descendant of Yngvi-Frey and who shared the Swedish kingship with his brother Alf.)
Also considered likely is a connection to the Ingaevones mentioned by Tacitus as one of the three primitive Germanic tribes descended from Mannus (the first man) son of Tuisto, being the peoples closest to the sea. In Nennius we find Mannus corrupted to Alanus and Ingio/Inguio ? his son to Neugio. Here the three sons of Neugio are Vandalus (ancestor of the Vandals, Saxo (father of the Saxons) and Boganus (ancestor of the Bogari).
Ingaevonic is often used in historical linguistics for a supposed Germanic proto-language from which descends English, Frisian and Low German.
The element Ing- in Old English names is usually considered cognate to Yngvi
The Old English Runic Poem contains these obscure lines:
- Ing wæs ærest mid Eástdenum
- gesewen secgum, oð he síððan eást
- ofer wæg gewát. wæn æfter ran.
- þus Heardingas þone hæle nemdon.
- Ing was first amidst the East Danes
- so seen, until he went eastward
- over the sea. His wagon ran after.
- Thus the Heardings named that hero.