In Ireland
When I speak of the ancient Celts, I am referring to the communities of people sharing linguistic and cultural ties who inhabited most of Northern Europe between 800 BCE and 400 CE. The folk of the Urnfield culture which preceded them may also have spoken a variety of Celtic, but they had not yet created the material culture that we identify with the Iron Age Celts. At the height of their expansion (4th-3rd centuries BCE) Celtic communities spread from Ireland to the Near East.
Hallstat culture (800-250 BCE), named after a type-site at Hallstatt, Austria, is the name given to the material culture of the early Iron Age Celts. Their range spanned from the Paris basin to valley of Morava in Eastern Europe and from the Alps to the north European plain. During early Hallstat (800-600 BCE) there is little evidence of great distinctions of wealth in burials. A few people are buried with wagons and horse gear, rather more are warriors (both genders) buried with their swords, most people are buried with personal ornaments and pots containing food. Cemeteries are small and associated with small settlements, perhaps one family or a group of related families.
Then between 600-450 BCE things begin to change as Mediterranean luxury goods begin to appear. Hilltop forts and a hierarchy of rich graves begins to appear. These aristocratic burials are associated with much larger residences inspired by Greek architectural styles. Archaeologists have suggested that paramount chief burial is accompanied by inhumation in a wooden chamber with wagon and horse trappings as before, but now there would also be a wide range of imported goods including bronze wine drinking vessels, silk, gold, amber, glass and coral. A vassal chief would be similar but the goods are more of local manufacture without the wide range of imports. Sub-chiefs are again similar but less elaborately furnished with totally local manufacture. Below this status wagon burials are not