Ptolemy's Map

Ptolemy's Map

(Random thoughts - to be organised into a more cogent flow)
 
Claudius Ptolemy (roughly AD 90–168) presents us the oldest surviving account of Ireland in the form of a set of coordinates showing different geographical features.

1. Note the presence of Menapii (with their coastal town Menapia) who inhabited coastal regions of Northern Gaul (see Map of Northern Gaul). O'Rahilly makes a linguistic case that the tribes shown here as Darini, Volunti (Ulaid) and Iverni (Erainn) are also Fir Bolg tribes, and closely related by virtue of a claimed common ancestor (Daire).
   However, the "Darini" are placed in a location known to have been dominated by the Cruthin "Dal nAraide" (pronounced DalAree) from the earliest known historical period until the 10th Century AD. It seems at least possible, if not likely, that Ptolemy's "Darini" represents the Cruthin Dal nAraide
2. There are no Goidelic/Gaelic ("Q" Celtic") names shown on Ptolemy's list of names (he used the word Magnata for what O'Connor believes was a Greek rendering of Cnoc na Dal), only "P" Celtic ("p" and not "q" in Manapii) and also the syllabic "n" is represented by "an" in Brigantes, not "en" as it would have been in Gaelic. Furthermore O'Rahilly notes that "Iverni" would have been written Everni (Ref 1: p17) in Gaelic.
3. So, strong evidence of the Brittonic "P-Celtic" speaking Fir Bolg, but no evidence for any Gaelic influence in this map.
4. O'Connor writes "Knocknadala (early Cnoc na nDál) was rendered by Ptolemy as NAG-NA-TA[ L ] and named by him as "the most illustrious city in all Britannia and the most considerable in size, located in the western part of Ireland"." Of course Tara is the eastern part of Ireland, near Dublin, nowhere near where Ptolemy places the great Gaelic Regia.

Links to different interpretations are shown here e.g. 

"Ptolemy’s map of Ireland: a modern decoding":R. Darcy and William Flynn
Department of Political Science, Oklahoma State University, Stillwater, USA

here   Taylor and Francis on-line, and the map shown below is their version