Editing Ligurian language (ancient) (section)

=== Substrate theories ===
In the late 19th century, [[Henri d'Arbois de Jubainville]] proposed that the Ligures constituted an early Indo-European substratum in Western Europe, separate from both Gaulish and Italic groups. Building on classical sources, he identified a range of place names and tribal names that did not fit neatly into known Celtic or Italic patterns. His theory, which came to be termed "Celto-Ligurian", influenced philological and archaeological approaches for the following decades. According to Bernard Mees, de Jubainville became "the intellectual grandfather to a genealogy of prehistorical and protohistorical substratum theories".{{sfn|Mees|2003|pp=16–18}}[[File:Old_European_hydronymic_map_for_the_root_*al-,_*alm-_Krahe.jpg|right|thumb|400x400px| [[Hans Krahe]]'s "[[Old European hydronymy|Old European]]" hydronymic map for the root ''*al-'', ''*alm-.'']]By the 1920s, scholars were using the "Celto-Ligurian" idea to explain problematic Indo-European toponyms and hydronyms across much of Europe. For instance, [[Paul Kretschmer]] argued that some inscriptions in Etruscan script (later identified as [[Lepontic language|Lepontic Celtic]]) provided evidence for a Ligurian linguistic layer, but subsequent discoveries established these as clearly Celtic with only limited Etruscan influence. In the 1930s, [[Julius Pokorny]] adopted these insights for his [[Pan-Illyrian hypotheses|pan-Illyrian]] (or "Illyro-Venetic") theory, linking it to the prehistoric [[Urnfield culture]]. Consequently, many difficult place-name etymologies were attributed to a hypothetical Illyrian layer, leading to broad, stratigraphical theories that traced Indo-European linguistic influences from Gaul all the way to the Balkans.{{sfn|Mees|2003|pp=16–18}}

By the late 1950s, Pokorny's theories had lost its momentum following critical scrutiny. The underlying place-name elements championed by de Jubainville and Pokorny, however, were reworked by [[Hans Krahe]] into his "[[Old European hydronymy|Old European]]" theory. Focusing on hydronyms, Krahe advanced a more refined approach, yet it remained conceptually indebted to de Jubainville's earlier "Celto-Ligurian" framework. Though Krahe proposed a more systematic argument than the earlier "Illyrian" or "Celto-Ligurian" frameworks, his theory still faced criticism for assuming that widespread, older Indo-European features belonged to one single language rather than several archaic dialects.{{sfn|Mees|2003|pp=16–18}}

Linguist [[James Clackson]] has criticized these approaches by stating that "the label 'Ligurian' merely serves to conceal our ignorance" about the pre-Roman linguistic landscape in various regions of Europe.{{sfn|Clackson|2015|pp=3–5}}