The Elder Futhark was a script, and the surviving evidence for it is inscriptions on objects rather than any body of text.
Fifteenth in the row
Algiz is the fifteenth character of the twenty-four character Elder Futhark, used for the earliest Germanic inscriptions from roughly the second century onward.
A sound with no comfortable transliteration
This character writes a sound that later became a variety of r in North Germanic, and editors transliterate it in several ways because no single Latin letter fits it. In the Younger Futhark its descendant character survives with a changed value and, eventually, a changed position in the row. A reader comparing editions will meet the same character under more than one symbol, and that is an editorial convention rather than a disagreement about what is on the object.
What survives
The corpus is short inscriptions on brooches, weapon fittings, combs, bracteates and stones, many of them personal names. It is small enough that a single new find can change the reading of a class of inscriptions.
The name
Algiz is a reconstruction, projected back from the names given in the medieval Old Norse and Old English rune poems to the characters of their own, later rows. Its meaning is not securely recovered, and the atlas records that rather than choosing one of the proposals.
Later use
The character was among those adopted in twentieth-century esoteric and then political contexts, a history recorded separately in this atlas and entirely distinct from the inscriptional record described here.