In Norse mythology, Aegir (King of the Sea) was one of three giants who lived with the Aesir. The other two are Lue (representing fire) and Kari (representing air)
The name Aegir is linked to the word for water, and he is the personification of the sea. His powers can be used for both good and evil, but are always related to water and the sea. The river Eider was also called "Aegir's door", and "Aegir's jaws" were the tidal waves and eddies that engulfed ships at sea. His counterparts are the Greek Poseidon and the Roman god Neptune.
Aegir is often presented as an old man with a white beard and claw-like fingers. If you saw him on the surface of the sea, it was usually an ominous sign. He usually comes to the surface with the intention of dragging ships and men with him to the bottom of the sea and was therefore naturally feared by sailors.
Aegir also possesses a large vessel called Aegor, given to him by Thor and Tyr. In this vessel he brews the mead of life from the blood of Baldr. The mead is synonymous with the life-giving sea. Life began in the salt sea, and after Ragnarok a new world will arise again from the sea.
According to Danish tradition, he lives on Læsø with the giantess Ran, a harsh woman who causes storms and shipwrecks.
According to Icelandic lore, Aegir and Ran lived in magnificent gold-plated halls under the sea on the island of Hlésey/Hléssey/Lessö, perhaps Læsø or an old name for the godforsaken island of Jan Mayen, a name from before 1614.
Aegir is friendly to the gods and often invites them to a feast. It is at a feast with Aegir that Loki in anger insults all the Aesir (Loki's quarrel), so that they finally lose patience with him and then seize him and chain him in the cave, where he will stand until Ragnarok.
Aegir's offspring are said to be the waves and his nine daughters are said to be the same as the nine mothers of the god Hejmdal. The names of Aegir's nine daughters were Himinglæva, Dufa, Blodughadda, Hefring, Ud, Hrønn, Bølge, Drøfn and Kolga, but the names are probably meant purely symbolically and poetically, they are all different words for the term "wave".
For the Vikings, the sea was the way to trade, gold and land, perhaps why Aegir is associated with wealth.
At Copenhagen City Hall there is a tile painting at the top of the presidential staircase on the 2nd floor (magistratstrappen) depicting Aegir. The picture was made by Reistrup (Kæhler) but designed by Lorentz Frølich.
The latter won a gold medal at the Great Exhibition in Chicago in 1893 (on the occasion of the 400th anniversary of the discovery of America) after which, on his return, the tile painting was placed in its permanent place in the Town Hall.
The painting is called "Aegir says goodbye to her daughters after a guest bid on Læsø" or simply "Aegir's guest bid". Based on the picture of Aegir, the rest of the staircase's fine stucco decorations are created (by the town hall's architect Martin Nyrop): in the staircase we see four ash trees, (yggdrasil, the tree of life) next to fishing nets hanging to dry.
The Øresund lies quietly in the background. In the ceiling, the sky is filled with seagulls signalling wealth under the sea: "here is food, here is life". The very large window in the staircase originally faced Kalvebod Strand (the main railway area) and "pointed" to the sea.
The overall picture is a legend of the birth of Copenhagen where Aegir is the life-giving force, which concretely manifested itself in the herring fishery that created the trading centre and which ultimately made the city interesting for Købmannahavn's founder Bishop Absalon.