linguistic:paraphrasing, stylistic:style_transfer
Urnfield-Hallstatt theory

The mainstream view during most of the twentieth century is that the Celts and the proto-Celtic language arose out of the Urnfield culture of central Europe around 1000 BC, spreading westward and southward over the following few hundred years. The Urnfield culture was preeminent in central Europe during the late Bronze Age, circa 1200 BC to 700 BC. The spread of iron-working led to the Hallstatt culture (c. 800 to 500 BC) developing out of the Urnfield culture in a wide region north of the Alps. The Hallstatt culture developed into the La Tène culture from about 450 BC, which came to be identified with Celtic art.

In 1846, Johann Georg Ramsauer unearthed an ancient grave field with distinctive grave goods at Hallstatt, Austria. Because the burials "dated to roughly the time when Celts are mentioned near the Danube by Herodotus, Ramsauer concluded that the graves were Celtic". Similar sites and artifacts were found over a wide area, which were named the 'Hallstatt culture'. In 1857, the archaeological site of La Tène was discovered in Switzerland. The huge collection of artifacts had a distinctive style. Artifacts of this 'La Tène style' were found elsewhere in Europe, "particularly in places where people called Celts were known to have lived and early Celtic languages are attested. As a result, these items quickly became associated with the Celts, so much so that by the 1870s scholars began to regard finds of the La Tène as 'the archaeological expression of the Celts'". This cultural network was overrun by the Roman Empire, though traces of La Tène style were still seen in Gallo-Roman artifacts. In Britain and Ireland, the La Tène style survived precariously to re-emerge in Insular art.

The Urnfield-Hallstatt theory began to be challenged in the latter 20th century, when it was accepted that the oldest known Celtic-language inscriptions were those of Lepontic from the 6th century BC and Celtiberian from the 2nd century BC. These were found in northern Italy and Iberia, neither of which were part of the 'Hallstatt' nor 'La Tène' cultures at the time. The Urnfield-Hallstatt theory was partly based on ancient Greco-Roman writings, such as the Histories of Herodotus, which placed the Celts at the source of the Danube. However, Stephen Oppenheimer shows that Herodotus seemed to believe the Danube rose near the Pyrenees, which would place the Ancient Celts in a region which is more in agreement with later classical writers and historians (i.e. in Gaul and Iberia). The theory was also partly based on the abundance of inscriptions bearing Celtic personal names in the Eastern Hallstatt region (Noricum). However, Patrick Sims-Williams notes that these date to the later Roman era, and says they suggest "relatively late settlement by a Celtic-speaking elite".