Classical-era Europe provides evidence of two major migration movements: the Celtic peoples (a collection of Indo-European peoples neither in Europe nor in Anatolia), and the later Migration Period from the North and East; both may be examples of general cultural change sparked by primarily elite and warrior migration.
The Celts (/klts, slts/, see pronunciation of Celt for different usages) are a collection of Indo-European peoples in parts of Europe and Anatolia identified by their use of the Celtic languages and other cultural similarities. 
