Frisians, a people of Teutonic stock, who, Tacitus says, when the Romans first came into contact with them, occupied the maritime region extending from the Scheldt to the Ems and Weser. They submitted to the Roman power in the reign of Drusus, and were loyal and helpful tributaries until stung into revolt in 28 A.D. by the extortions of a Roman provincial officer. From that time onwards they rendered only sullen submission to the empire, and more than once revolted and maintained their independence for some years. They were sea-rovers, as well as herdsmen and husbandmen, and took part along with the Angles and Saxons in the conquest of Britain. We next read of them as offering a stubborn resistance not only to the introduction of Christianity, but also to the encroachments of the Frankish power from the south; in fact, in spite of the efforts of Wilfrid of York, the first missionary among the Frisians, and his successors Willibrord and Boniface, the Christian religion does not seem to have obtained footing in Frisia beyond the actual limits of Frankish dominion until the complete absorption of the Frisians' land in the empire of Charlemagne. In the meantime they had waged an almost continuous war against the Franks. Their king Radbod, although driven out of western Frisia (from the Scheldt to the Zuider Zee) in 689 by Pepin, so far turned the tables after the death of this king that he sailed up the Rhine to Cologne, and defeated Charles Martel, in 716. Their last independent prince, Poppe, was defeated and slain by Charles Martel in 734, and the conquest of the Frisians was completed by Charlemagne. At the partition of the Frankish empire made at Verdun in 843 Frisia became part of Lotharingia or Lorraine. In 911, however, when Lotharingia seceded from the eastern to join the western Frankish empire, the districts of eastern Frisia (from the Zuider Zee to the Weser) asserted their independence, and formed themselves into a sort of democratic confederated republic, until in the first half of the 15th century they became virtually a county, being ruled by the dynasty of the Cirkseña down to the extinction of the family in 1744, when Prussia took possession of it. Meanwhile the western half of Frisia had for the most part been absorbed in the bishopric of Utrecht and the countship of Holland, though not without a most stubborn resistance on the part of the Frisians, a resistance which had not wholly died out by the end of the 15th century. In fact in 1457 the Emperor Frederick III. recognised their immediate dependence upon the empire. And it was only in 1498 that their staunch love of liberty was finally crushed by Albert of Saxony, whom Maximilian had appointed hereditary imperial governor of Frisia. From 1523, when the governorship fell to Charles V., Frisia became virtually a part of the Netherlands, and from that time onwards shared their destiny.
The Frisian language is a member of the Low German family, coming intermediate between Old Saxon and Anglo-Saxon. Its most striking peculiarity is the modification of h and g into ts before the letters e and i. The oldest existing specimens of the language do not go back beyond the 14th and 15th centuries, and consist principally of the old law codes and similar official documents (collected in Richthofen, Friesische Rechtsquellen, 1840). The celebrated Lex Frisionum, although it belongs probably to the period of Charlemagne, is composed in Latin, and contains a very meagre sprinkling of Frisian terms. At the present day pure Frisian is spoken only by the peasantry in the west of Dutch Friesland and in one or two isolated districts of Prussian East Friesland, and is cultivated by a small coterie of men of literary taste in Holland. Corrupt forms are spoken in Heligoland and in parts of Jutland and Sleswick. Gysbert Japiex occupies the first place amongst Frisian writers, having published in 1668 a volume of poems entitled Friesche Rijmerye. Other books held in great esteem by the Frisians are a comedy, Waatze Gribberts Briltoft, dating from the beginning of the 18th century, and the popular work, It Libben fen Aagtje Ijsbrants (1827). Het Oera Linda Bok, of which an English edition appeared in 1877, though purporting to be of vast antiquity, was really written by a ship-carpenter, Over de Linden (1811-73). Besides these, quite modern works have been written by E. and J. H. Halbertsma, Salverda, Posthumus, Windsma, Dykstra, Deketh, Van der Veen, Van Assen, and others. The most important production in northern Frisian, the corrupt dialect of Jutland and Sleswick, is Hansen's comedy De Gidts Hals. A society was founded at Franeker in 1829 for the study of the Frisian language and history.
The most complete accounts of Frisian literature are perhaps to be found in Mone, Uebersicht der niederländischen Volksliteratur älterer Zeit (1838), and Winkler, Allgemein niederdeutsch en friesch Dialecticon (1872). For the study of the language, see grammars by Rask, Grimm, Heyne, and A. H. Cummins (2d ed. Lond. 1888), grammars, dictionaries, &c. by Richthofen (1840), J. Halbertsma (1874), Cadovins Müller (died 1725), Ten Doornkaat-Koolman (1877-85), Dirksen (1889), Outzen (1837), Bendsen (1860), and Johansen (1862).