Celts (Lat. Celta; Gr.Celts 040093 ), a people of the Aryan or Indo-European family, who in prehistoric times, and probably before the migration of any other Aryan tribes, passed over from Asia into Europe. Subsequent migrations drove them gradually further and further to the westward; and after overspreading many regions in their passage (for evidences of their residence are found in most of the European countries), they appear at the very beginning of the historic period to have so entirely passed away from the eastern portion of the continent, and to have so firmly settled in the regions afterward called Transalpine Gaul and the British isles, that ancient historians believed them to be an autochthonous race, the natives and original possessors of those lands. This theory was strengthened by the fact that the tide of their progress now began to return upon itself; the earliest records showing that even at a remote period they sent out armies and emigrants toward the east, in a direction exactly opposite to the first current of their migration.

As early probably as the 5th century B. C. Celts had subdued that part of northern Italy afterward called from their later name Gallia (Cisalpina), and had become firmly settled in the country; they had planted vigorous colonies (Vindeli-cians, etc.) in southern Germany, near the E. bank of the Rhine; and from these in turn they penetrated, chiefly under the names of Rhoati, Boii, Norici, and Carui, into the western regions of modern Austria. Nearly all the territory now included in Switzerland seems also to have been held by them. Celtic tribes, too, had crossed the Pyrenees into Spain, and settled in the country; and from them and the Iberians, the older residents of the peninsula, sprung the mixed race of the Celtiberi, forming a famous nation in the centuries which followed. - The Spanish branch of the Celts was the first to find mention under the name of the race in authentic written records; and Herodotus only noticed this tribe briefly, as living "beyond the Pillars of Hercules, and bordering on the Cynesians, who dwell at the extreme west of Europe." (Book ii., 33.) But soon after his time the great body of the Celtic race began to fill a prominent place in general history.

About 390 B. C, according to what is little more than a historical tradition, vast hordes of Celts, under their leader Brennus (a word probably equivalent merely to general or king), poured into Italy and sacked Rome, from which they were driven by Camillus. About the same period others appeared along the lower Danube, and succeeded in the establishment of an enduring power there. From this colony many formidable armies went out to carry devastation through Thrace, Macedonia, and Greece. In 280 B. C. one of these, under another Brennus, poured its overwhelming numbers into the kingdom of Ptolemy Ceraunus, defeated and killed that monarch, overran Thessaly, entered central Greece at Thermopylas, and reached Delphi with the intention of destroying it, when they were at last successfully opposed and driven back. They founded at the same time a kingdom in Thrace, which remained for many years a formidable power, but was finally destroyed by the Thracians around it. - From the same branch of the Celts which sent out these armies (a branch often called the Illyrian Celts from the district, Illyricum, in which their place of settlement was subsequently included) sprung also another offshoot.

This consisted of an army which, about the time of the expedition of the second Brennus, crossed the Hellespont into Asia Minor, and appears to have overrun much of the peninsula, until at last the invaders were compelled to confine themselves to the region called after them Galatia. This was successfully held by them, and they established there one of the most enduring of their kingdoms, in which they long preserved many peculiarities of the race. - In the earliest writings the Celts had been calledCelts 040094 (Celtael); but as they became better known to the Greeks and Romans, the names Galii and Ga-lataaCelts 040095 were more commonly applied to them, these being probably nothing more than corrupted forms of the original word. The names were for a long time used indiscriminately of all the race; but gradually their application was limited - Galli (Gauls) signifying those who lived in Europe; Galatre (Galatians), those who settled in Asia Minor; while the name Celtaa gradually disappeared. The looseness with which ancient writers use the word Galli, employing it now to denote a Teutonic, now a Celtic people, and generally understanding it to mean any northern barbarians, whoever they were, is perhaps the greatest cause of our inability to trace with exactness the gradual decline of the Celts before the advance of other races. Their career after the various wanderings and settlements we have noticed becomes inextricably involved with that of other peoples; and all that can be affirmed with certainty concerning them is the fact that they were gradually absorbed into the Roman, Germanic, and mixed races that overran Europe during the centuries which followed the beginning of the period of authentic history.

In this way they became merely an element in the formation of the nations now populating the European continent, and as a distinct power entirely disappeared from all the region they once had occupied. But although they no longer form an independent nation or people, there remain in the British isles, and in a district of Brittanv in France, descendants of the race who retain many of its prominent characteristics, and who continue to make use of different dialects of the ancient Celtic languages. In Wales, Ireland, and the Scottish highlands are found the most marked and distinct types of these; while but a short time has passed since the dying out of a branch of the Celtic race in Cornwall. (See BelgAE, Celtiberians, Cimbri, Cimmerii, and Gaul.)