Árheimar was a capital of the Goths

Goths

The Goths were an East Germanic tribe of Scandinavian origin whose two branches, the Visigoths and the Ostrogoths, played an important role in the fall of the Roman Empire and the emergence of Medieval Europe....

, according to the Hervarar saga

Hervarar saga

Hervarar saga ok Heiðreks is a legendary saga from the 13th century combining matter from several older sagas. It is a valuable saga for several different reasons beside its literary qualities. It contains traditions of wars between Goths and Huns, from the 4th century, and the last part is used as...

. The saga only states that it was located on the river Dnieper, which flows from Ukraine to the Black Sea.

Hervarar saga

The name first appears in the Hervarar saga when Angantyr

Angantyr

Angantyr was the name of three characters from the same line in Norse mythology, and who appear in Hervarar saga, in Gesta Danorum and Faroese ballads....

 has avenged his father Heidrek

Heidrek

Heidrek or Heiðrekr was one of the main characters in the cycle about the magic sword Tyrfing. He appears in the Hervarar saga, and probably also in Widsith, line 115, as Heathoric together with his sons Angantyr and Hlöð , and Hlöð's mother Sifka...

 and retaken the Dwarf-cursed sword Tyrfing

Tyrfing

Tyrfing or Tirfing was a magic sword in Norse mythology, which figures in a poem from the Poetic Edda called Hervararkviða, and in Hervarar saga...

:

"And when it was close on midnight, Angantyr went up to them and pulled them down the tent on top of the slaves and slew all nine of them, and carried off the sword Tyrfing as a sign that he had avenged his father. He then went home and had a great funeral feast held to his father's memory on the banks of the Dnieper, at a place called Arheimar."

It was during this feast that Angantyr's Hunnish half-brother Hlöd

Hlöd

Hlod or Hlöd was the illegitimate son of Heidrek, the king of the Goths.He appears in the Hervarar saga and probably also as Hlith in Widsith, line 115, together with his father Heiðrekr , half-brother Angantyr , and his mother Sifka .-Claiming his inheritance:Hlöd had grown up with his grandfather...

 appeared with a large army to demand half the inheritance:

"Hlöth , the heir of Heithrek,

Came riding from the East,

To where Angantyr was holding

King Heithrek's funeral feast.

He came to his court in Arheimar

Where the Gothic people dwell,

Demanding his share of the heritage left

By the King when he journeyed to Hell."

The next place is when Angantyr's brave sister Hervor

Hervor

Hervor is the name of two female characters in the cycle of the magic sword Tyrfing, presented in Hervarar saga with parts found in the Poetic Edda. The first Hervor was the daughter of Angantyr...

 fights the Huns, although, her small army is greatly outnumbered by the Horde and she knows she cannot win:

"Then Ormar rode back to the fortress, and found Hervör and all her host armed and ready. They rode forthwith out of the fort with all their host against the Huns, and a great battle began between them. But the Hunnish host was far superior in numbers, so that Hervör's troops began to suffer heavy losses; and in the end Hervör fell, and a great part of her army round about her. And when Ormar saw her fall, he fled with all those who still survived. Ormar rode day and night as fast as he could to King Angantyr in Arheimar. The Huns then proceeded to ravage and burn throughout the land."

Arheimar is mentioned for the last time, when the Geatish king Gizur

Gizur

Gizur, Gizurr or Gissur was a King of the Geats. He appears in The Battle of the Goths and Huns, which is included in the Hervarar saga and in editions of the Poetic Edda...

 has arrived with his army from Scandinavia

Scandinavia

Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...

 to fight for the Goths, and tells the Huns where they and the Goths are to meet the Huns in battle. Hlöd demeans Gizur by calling him an Ostrogoth

Ostrogoth

The Ostrogoths were a branch of the Goths , a Germanic tribe who developed a vast empire north of the Black Sea in the 3rd century AD and, in the late 5th century, under Theodoric the Great, established a Kingdom in Italy....

 (Gryting

Greuthungi

The Greuthungs, Greuthungi, or Greutungi were a Gothic people of the Black Sea steppes in the third and fourth centuries. They had close contacts with the Thervingi, another Gothic people from west of the river Dnestr. They may be the same people as the later Ostrogoths.-Etymology:"Greuthungi" may...

) and Angantyr's man from Arheimar, and not a king of the Geats:

"When Hlöth heard Gizur's words, he cried:

'Lay hold upon Gizur of the Grytingar. Angantyr's man, who has come from Arheimar!'

King Humli said: 'We must not injure heralds who travel about unattended.'

Gizur cried: 'You Hunnish dogs are not going to overcome us with guile.'

Then Gizur struck spurs into his horse and rode back to King Angantyr, and went up to him and saluted him. The King asked him if he had parleyed with the Huns.

Gizur replied: 'I spoke with them and I challenged them to meet us on the battle-field of Dunheith [i.e. the plains of the Danube

Danube

The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....

] and in the valleys of Dylgia.'"