Old European hydronymy

[1][note 1] Krahe writes in A1, chapter III, "Introducing preface" Number 2[1]: 32  that the old European hydronomy extended from Scandinavia to South Italy, from Western Europe including the British Isles to the Baltic countries.

[1]: 12  This area is associated with the spread of the later "Western" Indo-European dialects, the Celtic, Italic, Germanic, Baltic, and Illyrian branches.

Krahe located the geographical nucleus of this area as stretching from the Baltic across Western Poland and Germany to the Swiss plateau and the upper Danube north of the Alps, while he considered the Old European river names of southern France, Italy and Spain to be later imports, replacing "Aegean-Pelasgian" and Iberian substrates,[1]: 81  corresponding to Italic, Celtic and Illyrian "invasions" from about 1300 BC.

Both rules are important arguments for considering the old European hydronomy of southern France and the north of the Iberian Peninsula as a result of secondary implementation (A 1, number 3) due to a postulated immigration about 1300 BC.

In "Morphology of Paleoeuropean river names" (III A 1, number 3), Krahe concentrates on suffixes (simples and multiples) and distinguishes eleven different ones in a table.

Krahe ignored the effect of the Moorish occupation in Spain, which resulted in frequent combinations of Arab "prefixes" (always at the beginning) on Celtic "suffixes" as seen in Guadiana (guadi "river" + anas "bayous, muddy", as it appears in Ptolemy).

Jürgen Untermann, a disciple of Krahe, whose dissertation was written in 1954 in Tübingen was professor for comparative linguistics at the University of Cologne.

[4] The Spanish philologist Francisco Villar Liébana argued in 1990 for Old European preserved in river names and confined to the hydronymic substratum in the Iberian Peninsula as yet another Indo-European layer with no immediate relationship to the Lusitanian language.