JINGO, a legendary empress of Japan, wife of Chflai, the 14th mikado (191-200). On her husband's death she assumed the government, and fitted out an army for the invasion of Korea (see Japan, 9). She returned to Japan completely victorious after three years' absence. Subsequently her son Ojen Tenno, afterwards isth mikado, was born, and later was canonized as Hachiman, god of war. The empress Jingo ruled over Japan till 270. She is still worshipped.
As regards the English oath, usually " By Jingo," or " By the living Jingo," the derivation is doubtful. The identification with the name of Gingulph or Gengulphus, a Burgundian saint who was martyred on the i ith of May 760, was a joke on the part of R. H. Barham, author of the Ingoldsby Legends. Some explain the word as a corruption of Jainko, the Basque name for God. It has also been derived from the Persian jang (war), St Jingo being the equivalent of the Latin god of war, Mars; and is even explained as a corruption of " Jesus, Son of God," Je-n-go. In support of the Basque derivation it is alleged that the oath was first common in Wales, to aid in the conquest of which Edward I. imported a number of Basque mercenaries. The phrase does not, however, appear in literature before the 17th century, first as conjurer's jargon. Motteux, in his " Rabelais," is the first to use " by jingo," translating par dieu. The political use of the word as indicating an aggressive patriotism (Jingoes and Jingoism) originated in 1877 during the weeks of national excitement preluding the despatch of the British Mediterranean squadron to Gallipoli, thus frustrating Russian designs on Constantinople. While the public were on the tiptoe of expectation as to what policy the government would pursue, a bellicose music-hall song with the refrain " We don't want to fight, but by Jingo if we do," etc., was produced in London by a singer known as " the great MacDermott," and instantly became very popular. Thus the war-party came to be called Jingoes, and Jingoism has ever since been the term applied to those who advocate a national policy of arrogance and pugnacity.
For a discussion of the etymology of Jingo see Notes and Queries, (August 25, 1894), 8th series, p. 149.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)