The first mention of the “Green Elves” was in the earliest Lost Tales, where a group of Elves “clad in green and brown” came to the aid of Beren to avenge the death of Tinwelint, precursor to Thingol (LT2/234). Presumably at this stage they were part of the Ilkorin elves and spoke one of their various languages. In the Silmarillion drafts from the beginning of the 1930s, this group Elves took on the role they would take in Tolkien’s later stories, but at first they were only called the “Green-elves” (SM/133). Soon after, Tolkien coined the name Danian or Danas and defined the characteristics of their language distinct from the other Eldar (PE19/18).

In the Comparative Tables, Tolkien first grouped Danian with Ilkorin, declaring that they were both languages of “Germanic” type (PE19/22 note #54). Tolkien changed his mind, deciding that Ilkorin was more Welsh-like, as Noldorin “used to be”, that is more like the Gnomish of Tolkien’s earlier writings. The Ilkorin columns were the relabeled Danian and new Ilkorin columns were added (PE19/18 note #2, PE19/19 note #11). The Early Ilkorin words attested in Early Noldorin notes from the 1920s also had a Germanic character, as suggested by Roman Rausch and Helios Martínez (HPITN, EIP), and thus was more of a conceptual pre-cursor to Danian than of later Ilkorin of the 1930s.

Later still Tolkien referred to this group of Elves as the Nandor, and their language as Nandorin. See the discussion of the Nandorin language for further details.