''The Proto-Albanian language is the unattested language from which Albanian later developed. Albanian evolved from an ancient Paleo-Balkan language, traditionally thought to be Illyrian,[3] or otherwise a totally unattested Balkan Indo-European language that was closely related to Illyrian and Messapic,[4] which is sometimes also referred to as Albanoid.[5]''

''Proto-Albanian is reconstructed by way of the comparative method between the Tosk and Gheg dialects, as well as the treatment of loanwords, the most important of which are those from Latin (dated by De Vaan to the period 167 BCE to 400 CE) and from Slavic (dated from 600 CE onward).[4] The evidence from loanwords allows linguists to construct in great detail the shape of native words at the points of major influxes of loans from well-attested languages.[6]"

"What is for Orel "Early Proto-Albanian" (EPA), dated definitively before the onset of Latin contact, is for De Vaan, "Pre-Proto-Albanian" (PPAlb); in German, this stage is called Voruralbanisch or Frühuralbanisch.[4] De Vaan also discusses the possibility of breaking Pre-Proto-Albanian into two stages: one before the first Greek loanwords, and one that is after the first Greek loanwords, but before contact with Latin.[4"

https://en.m.wikipedia.org/wiki/Proto-Albanian_language