East Dane is an Anglo-Saxon

Anglo-Saxons

Anglo-Saxon is a term used by historians to designate the Germanic tribes who invaded and settled the south and east of Great Britain beginning in the early 5th century AD, and the period from their creation of the English nation to the Norman conquest. The Anglo-Saxon Era denotes the period of...

 ethnonym which was used in the epic Beowulf

Beowulf

Beowulf , but modern scholars agree in naming it after the hero whose life is its subject." of an Old English heroic epic poem consisting of 3182 alliterative long lines, set in Scandinavia, commonly cited as one of the most important works of Anglo-Saxon literature.It survives in a single...

as a kenning

Kenning

A kenning is a type of literary trope, specifically circumlocution, in the form of a compound that employs figurative language in place of a more concrete single-word noun. Kennings are strongly associated with Old Norse and later Icelandic and Anglo-Saxon poetry...

 for the Geats, the people of Götaland

Götaland

Götaland , Gothia, Gothland, Gothenland, Gautland or Geatland is one of three lands of Sweden and comprises provinces...

 without Scania

Scania

Scania is the southernmost of the 25 traditional non-administrative provinces of Sweden, constituting a peninsula on the southern tip of the Scandinavian peninsula, and some adjacent islands. The modern administrative subdivision Skåne County is almost, but not totally, congruent with the...

 in southern Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

.

It was also used in an Anglo-Saxon runic poem describing the first appearance of the god Frey (called Ing, see Yngvi

Yngvi

Yngvi, Yngvin, Ingwine, Inguin are names that relate to an older theonym Ing and which appears to have been the older name for the god Freyr ....

):

Ing wæs ærest mid Eástdenum

gesewen secgum, oð he síððan eást

ofer wæg gewát. wæn æfter ran.

þus Heardingas þone hæle nemdon.

Ing was first amidst the East Danes

so seen, until he went eastward

over the sea. His wagon ran after.

Thus the Heardings named that hero.

In Scandinavian mythology (Ynglinga saga

Ynglinga saga

Ynglinga saga is a legendary saga, originally written in Old Norse by the Icelandic poet Snorri Sturluson about 1225. It was first translated into English and published in 1844....

 and Gesta Danorum

Gesta Danorum

Gesta Danorum is a patriotic work of Danish history, by the 12th century author Saxo Grammaticus . It is the most ambitious literary undertaking of medieval Denmark and is an essential source for the nation's early history...

), the first appearance of Frey was localised to Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 and Old Uppsala, where he founded the Temple at Uppsala

Temple at Uppsala

The Temple at Uppsala was a religious center in Norse paganism once located at what is now Gamla Uppsala , Sweden attested in Adam of Bremen's 11th century work Gesta Hammaburgensis ecclesiae pontificum and in Heimskringla, written by Snorri Sturluson in the 13th century...

:

The Ynglinga saga:

Frey built a great temple at Upsal, made it his chief seat, and gave it all his taxes, his land, and goods. Then began the Upsal domains, which have remained ever since.http://www.northvegr.org/lore/heim/000_02.php

Gesta Danorum:

Also Frey, the regent of the gods, took his abode not far from Upsala, where he exchanged for a ghastly and infamous sin-offering the old custom of prayer by sacrifice, which had been used by so many ages and generations. For he paid to the gods abominable offerings, by beginning to slaughter human victims.http://sunsite.berkeley.edu/OMACL/DanishHistory/book3.html

Since Dane was used as a generic expression for Scandinavian, it can be hypothesized that the name East Dane of the runic poem refers to Scandinavians living east of the Danes proper (i.e. Swedes and Geats).