TSAR, or CZAR, the title commonly given both abroad and in Russia itself to the sovereign of Russia, whose official style is, however, " Emperor and Autocrat " (Imperator i Samovlastityel). In its origin the word tsar seems to have connoted the same as imperator, being identical with the German Kaiser in its derivation from the Latin Caesar. In the old Slavonic Scriptures the Greek /3acriXeus is always translated tsar, and this title was also given to the Roman Emperor. The old Russian title for a sovereign was knyaz, prince, or veliky knyaz, grand prince. The title tsar was first adopted by the Slavonic peoples settled in the Balkan peninsula, who were in close touch with the Eastern emperor; thus it was used by the medieval Bulgarian kings. It penetrated into Russia as a result of the growing intercourse between old Muscovy and Constantinople, notably of the marriage alliances contracted by Russian princes with the dynasty of Basil the Macedonian; and it was assumed by the Muscovite princes who revolted from the yoke of the Mongols. The other tsars were gradually ousted by those of Moscow, and the modern Russian emperors inherit their title of tsar from Ivan III. (1462-1505), or perhaps rather from his grandson Ivan IV. (1533-1584) who was solemnly crowned tsar in 1547.
Throughout, however, the title tsar was used, as it still is in popular parlance, indifferently of both emperors and kings, being regarded as the equivalent of the Slavonic krol or kral (Russ. korol, Magyar, kirdly), a king, which had been adopted from the name of Charlemagne (Germ. Karl, Lat. Carolus Magnus). Thisuse being equivocal, Peter the Great, at the peace of Nystad (Novembers, 1721), assumed the style of imperator, an exotic word intended to symbolize his imperial dignity as the equal of the western emperor. This new style was not, however, recognized by the powers until the time of Catherine II., and then only on the express understanding that this recognition did not imply any precedency or superiority of the Russian emperor over other sovereigns. Henceforth, whatever popular usage might be, the title tsar was treated officially as the equivalent of that of king. Thus the Russian emperor is tsar (king) of Poland and of several other parts of his dominions. Thus, too, the prince of Bulgaria, on assuming the royal style, took the title of tsar of Bulgaria.
The title ." White Tsar, applied to the Russian emperor and commonly quoted as though it had a poetic or mystic meaning, is a translation of a Mongol word meaning " independent " (cf. the feudal " blanch tenure, " i.e. a tenure free from all obligation of personal service).
The wife of the tsar is tsaritsa. In former times the title tsarevich (king's son) was borne by every son of a tsar; but the word has now fallen out of use. The heir to the throne is known as the tsesarevich or cesarevich (q.v.), i.e. son of Caesar, the other Imperial princes bearing the old Russian title of veliky knyaz (grand duke; q.v.).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)