For a seafaring people the sea was both at once: road and grave, riches and death. In the North this double nature took on two faces – Ægir, the hospitable lord of the deep, and Rán, his wife, who draws the drowned to herself with her net.
Ægir (Old Norse Ægir, ‘the sea’) is a sea-giant, yet he is treated like a god – a being of his own ancient order, neither wholly Æsir nor foe of the gods. His other name is Hlér (the Danish island of Læsø, ‘Hlésey’, is named after him). His wife Rán (Old Norse Rán, ‘robbery’) is the darker half: to her belongs whatever the sea swallows.
Ægir is famous as the brewer and host of the gods. In his hall on the sea floor, where bare gold shines instead of fire, he brews mead and ale for the Æsir in an enormous cauldron. To obtain that cauldron in the first place, Thor must first wrest it from the giant Hymir (told in the Hymiskviða). At one of these feasts the great scandal then erupts: Loki bursts in and heaps scorn and mockery on the assembled gods – the Lokasenna, the ‘flyting’.
“At Ægir’s the Æsir drank their ale,
gold shone instead of firelight in the hall.”
— image after the Poetic Edda (sense following Karl Simrock, 1851, public domain)
As kindly as Ægir seems, so uncanny is Rán. She owns a great net with which she drags sailors into the deep. Whoever drowns at sea ‘goes to Rán’ – her realm is the death-world of the drowned. An old custom is said to have answered this: sailors were given gold to take on their voyage so that, should they drown, they would not appear before Rán empty-handed. The gold on the sea floor is her treasure – hence the skaldic kenning ‘Rán’s fire’ for gold.

Heimdall & the Nine Mothers · Thor (Hymir’s Cauldron) · Loki (Lokasenna) · The Norse pantheon · The Nine Worlds.
Poetic Edda: Hymiskviða, Lokasenna (prose frame). Snorri Sturluson, Prose Edda (Skáldskaparmál: Ægir, Rán, sea-kennings), c. 1220. German public-domain translation: Karl Simrock, Die Edda (1851). Scholarship: Rudolf Simek, Dictionary of Northern Mythology; John Lindow, Norse Mythology (2001).