[2] Egil was born in Iceland, to Skalla-Grímr Kveldúlfsson[3] and Bera Yngvarsdóttir; he was the grandson of Kveld-Úlfr (whose name means 'evening wolf').

He exhibited berserk behaviour, and this, together with the description of his large and unattractive head, has led to the theory that he might have suffered from Paget's disease, which causes a thickening of the bones and may lead eventually to blindness.

[7] After Berg-Önundr refused to allow Egil to claim his wife Ásgerðr's share of her father's inheritance, he challenged Önundr to a man-to-man fight on an island (a hólmganga).

Later, after being grievously insulted, Egil killed Bárðr of Atley, a retainer of King Eiríkr Bloodaxe and kinsman of Queen Gunnhildr, both of whom spent the remainder of their lives trying to take vengeance.

In spring Þórólfr and Egil prepared a large warship and raid along the Eastern route (Austrvegr), where they won much wealth and had many battles.

In order to secure his place as sole King of Norway, Eiríkr Bloodaxe murdered his two brothers.

Egil sought out the house of his good friend Arinbjörn, where they armed themselves and marched to Eiríkr's court.

The complex nature of these poems, with complex poetic metres and metaphors (including kennings), as well as the fact that they were often about kings reliably attested in the historical record, provides some basis for supposing that they might have been composed by a historically real Egil Skallagrímsson, descending more or less unchanged through oral tradition from the time of their composition to the writing of Egils saga.

[9] Ultimately, Egil returned to his family farm in Iceland, where he remained a force to be reckoned with in local politics.

When a Christian chapel was constructed at the family homestead, Egil's body was exhumed by his son and re-buried near the altar.

According to the saga, the exhumed skull bone was hit with an axe, and it turned white, showing the strength of the warrior, but also, according to one modern interpretation, suggesting the traits of Paget's disease.

[10] In chapter 55 of Egil's Saga, his appearance is described as follows Egil was large-featured, broad of forehead, with large eyebrows, a nose not long but very thick, lips wide and long, chin exceeding broad, as was all about the jaws; thick-necked was he, and big-shouldered beyond other men, hard-featured, and grim when angry.

Runes were also employed by Egil during the raising of the Nithing Pole against King Eirik Bloodaxe and Queen Gunnhildr.