 Mallory proposed in 2013 that the Beaker culture was associated with a European branch of Indo-European dialects, termed "North-west Indo-European", ancestral to not only Celtic but also Italic, Germanic, and Balto-Slavic.The earliest written form of the Irish language is known to linguists as Primitive Irish.Primitive Irish is known only from fragments, mostly personal names, inscribed on stone in the Ogham alphabet.