Egill was born in Iceland, and was the son of Skalla-Grímr Kveldúlfsson and Bera Yngvarsdóttir, and the grandson of Kveld-Úlfr ("Night Wolf").
His ancestor, Hallbjorn, was Norwegian-Sami.

When Grímr arrived in Iceland, he settled at Borg, the place where his father's coffin landed.
Grímr was a respected chieftain and mortal enemy of King Harald Fairhair of Norway.

Egill composed his first poem at the age of three years.
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.

At the age of seven, Egill was cheated in a game with local boys.
Enraged, he went home and procured an axe, and returning to the boys, split the skull to the teeth of the boy who cheated him.
 After Berg-Önundr refused to allow Egill to claim his wife Ásgerðr's share of her father's inheritance, he challenged Önundr to a man-to-man fight on an island or holmgang.
Berg-Önundr refused the challenge and was later killed along with his brother Hadd by Egill.
Egill was later to kill the last of the brothers, Atli the Short, by biting through Atli's neck during a holmgang.

Later, after being grievously insulted, Egill killed Bárðr of Atley, a retainer of King Eirik Bloodaxe and kinsman of Queen Gunnhildr, both of whom spent the remainder of their lives trying to take vengeance.
Seething with hatred, Gunnhildr ordered her two brothers to assassinate Egill and his brother Þórólfr, who had been on good terms with her previously.
However, Egill slew the Queen's brothers when they attempted to confront him.
Gunnhildr's brother's names were Eyvind Braggart and Alf Aksmann.

In spring Þórólfr and Egill got ready a large warship and went the Eastern route (Austrvegr), where they won much wealth and had many battles.
In Courland they made a peace for half a month and traded with the men of the land. (
ch.
46).

That same summer, Harald Fairhair died.
In order to secure his place as sole King of Norway, Eirik Bloodaxe murdered his two brothers.
He then declared Egill an outlaw in Norway.
Berg-Önundr gathered a company of men to capture Egill, but was killed in his attempt to do so.
Before escaping from Norway, Egill also slew Rögnvaldr, the son of King Eirik and Queen Gunnhildr.
He then cursed the King and Queen, setting a horse's head on a Nithing pole and saying,
"Here I set up a níð-pole, and declare this níð against King Eiríkr and Queen Gunnhildr,"—he turned the horse-head to face the mainland—"I declare this níð at the land-spirits there, and the land itself, so that all will fare astray, not to hold nor find their places, not until they wreak King Eiríkr and Gunnhildr from the land."
He set up the pole of níð in the cliff-face and left it standing; he faced the horse's eyes on the land, and he carved runes upon the pole, and said all the formal words of the curse. (
ch.
57).

Gunnhildr also put a spell on Egill, which made him feel restless and depressed until they met again.

Soon afterwards, Eiríkr and Gunnhildr were forced to flee to the Kingdom of Northumbria by Prince Hákon.
In Saxon England, they were set up as King and Queen of Northumbria in rivalry with King Athelstan of England.
Ultimately, Egill was shipwrecked in Northumbria and came to know who ruled the land.
Egill sought out the house of his good friend Arinbjorn where they armed themselves and marched to Eiríkr's court.
Arinbjorn told Egill “now you must go and offer the king your head and embrace his foot.
I will present your case to him.”
 Arinbjorn presented Egill’s case and Egill composed a short drápa, reciting it with Eirikr’s foot in his hand, but Eirikr was not impressed.
He explained that Egill’s wrongs to him were far too great to be forgiven so easily.
 Gunnhild called for the immediate execution of Egill, but Arinbjorn convinced the king not to kill him until the morning.

The Vikings deemed it illegal to kill a man during the night time.
Arinbjorn told Egill that he should stay up all nigh
Egill was born in Iceland, and was the son of Skalla-Grímr Kveldúlfsson and Bera Yngvarsdóttir, and the grandson of Kveld-Úlfr ("Night Wolf"). His ancestor, Hallbjorn, was Norwegian-Sami.
When Grímr arrived in Iceland, he settled at Borg, the place where his father's coffin landed. Grímr was a respected chieftain and mortal enemy of King Harald Fairhair of Norway.
Egill composed his first poem at the age of three years. 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.
At the age of seven, Egill was cheated in a game with local boys. Enraged, he went home and procured an axe, and returning to the boys, split the skull to the teeth of the boy who cheated him.  After Berg-Önundr refused to allow Egill to claim his wife Ásgerðr's share of her father's inheritance, he challenged Önundr to a man-to-man fight on an island or holmgang. Berg-Önundr refused the challenge and was later killed along with his brother Hadd by Egill. Egill was later to kill the last of the brothers, Atli the Short, by biting through Atli's neck during a holmgang.
Later, after being grievously insulted, Egill killed Bárðr of Atley, a retainer of King Eirik Bloodaxe and kinsman of Queen Gunnhildr, both of whom spent the remainder of their lives trying to take vengeance. Seething with hatred, Gunnhildr ordered her two brothers to assassinate Egill and his brother Þórólfr, who had been on good terms with her previously. However, Egill slew the Queen's brothers when they attempted to confront him. Gunnhildr's brother's names were Eyvind Braggart and Alf Aksmann.
In spring Þórólfr and Egill got ready a large warship and went the Eastern route (Austrvegr), where they won much wealth and had many battles. In Courland they made a peace for half a month and traded with the men of the land. (ch. 46).
That same summer, Harald Fairhair died. In order to secure his place as sole King of Norway, Eirik Bloodaxe murdered his two brothers. He then declared Egill an outlaw in Norway. Berg-Önundr gathered a company of men to capture Egill, but was killed in his attempt to do so. Before escaping from Norway, Egill also slew Rögnvaldr, the son of King Eirik and Queen Gunnhildr. He then cursed the King and Queen, setting a horse's head on a Nithing pole and saying,
"Here I set up a níð-pole, and declare this níð against King Eiríkr and Queen Gunnhildr,"—he turned the horse-head to face the mainland—"I declare this níð at the land-spirits there, and the land itself, so that all will fare astray, not to hold nor find their places, not until they wreak King Eiríkr and Gunnhildr from the land." He set up the pole of níð in the cliff-face and left it standing; he faced the horse's eyes on the land, and he carved runes upon the pole, and said all the formal words of the curse. (ch. 57).
Gunnhildr also put a spell on Egill, which made him feel restless and depressed until they met again.
Soon afterwards, Eiríkr and Gunnhildr were forced to flee to the Kingdom of Northumbria by Prince Hákon. In Saxon England, they were set up as King and Queen of Northumbria in rivalry with King Athelstan of England. Ultimately, Egill was shipwrecked in Northumbria and came to know who ruled the land. Egill sought out the house of his good friend Arinbjorn where they armed themselves and marched to Eiríkr's court. Arinbjorn told Egill “now you must go and offer the king your head and embrace his foot. I will present your case to him.”  Arinbjorn presented Egill’s case and Egill composed a short drápa, reciting it with Eirikr’s foot in his hand, but Eirikr was not impressed. He explained that Egill’s wrongs to him were far too great to be forgiven so easily.  Gunnhild called for the immediate execution of Egill, but Arinbjorn convinced the king not to kill him until the morning.
The Vikings deemed it illegal to kill a man during the night time. Arinbjorn told Egill that he should stay up all nigh
Egill Skallagrímsson