Pre-Celtic

The Únětice Culture (c. 2300 BC - 1600 BC) was an early Bronze Age culture named for the first site of this type found NW of the city of Prague in Czechoslovakia).  It has been considered a possible precursor civilization which led to the development of the Celtic culture. 

It may have arisen from a fusion of the earlier Bell Beaker & Battle Axe cultures.

The Tumulus culture (c.1500 BC), so-called from their burial practices, involving inhumation in large mounds, then appeared, followed by the Urnfield culture (c. 1000 BC). again named after their burial practices, which revolved around cremations which were then buried in urns. These may have been proto-Celtic, as they exhibit some of the characteristics that we now associate with the Celts.

However, theories regarding the Urnfield people as proto-Celtic invaders have been under much revision of late. Some scholars now adhere to the theory that the new culture was a branching of pre-existing local cultures. As with all theories, as remarked earlier, it is subject to change and debate.

It seems likely that sometime prior to ca. 1200 BC there were social upheavals, as evidenced by changes in housing, increased fortifications, apparent abandonment of former trade and population centers following fires and apparent warfare. It seems likely that the local people became subordinated from without or within by an aristocratic, tripartite, horse-warrior culture.  Burials with grave-goods show a more clearly defined gap between classes. These finds represent a culture that seems to prefigure that of the Celts.

The next successor culture (Hallstatt) has been recognized by most scholars as definitely "Celtic."