BULGARUS, the most celebrated of the famous "Four Doctors" of the law school of Bologna. He is sometimes erroneously called Bulgarinus, which was properly the name of a jurist of the 15th century. Bulgarus was a native of Bologna, and was regarded as the Chrysostom of the Gloss-writers, being frequently designated by the title of the " Golden Mouth " los aureum). The time of his birth is not known. A popular tradition represents him to have been a pupil of Irnerius, but unfortunately nothing is known of lrnerius after 1118 A.D. Bulgarus, on the other hand, died in 1166 A.D., having attained a great age, and having become childish before his death. There is thus no inseparable difficulty in point of time in accepting this tradition as far as regards Bulgarus, although Savigny considers the general tradition to be inadmissible which represents all the Four Doctors to have been pupils of Irnerius. Martinus Gosia was the next most celebrated of the Four Doctors. He and Bulgarus were the chiefs of two opposite schools at Bologna, corresponding in many respects to the Proculians and Sabinians of Imperial Rome, Martinus being at the head of a school which accommodated the law to what his opponents styled the equity of "the purse " (aquitas bursalis), whilst Bulgarus adhered more closely to the letter of the law. The school of Bulgarus ultimately prevailed, and it numbered amongst its adherents Joannes Bassianus, Azo, and Accursius, each of whom in his turn exercised a commanding influence over the course of legal studies at Bologna. Bulgarus took the leading part amongst the Four Doctors at the diet of Roncaglia in 1158, and was one of the most trusted advisers of the Emperor Frederick I. His most celebrated work is his commentary De Regulis Juris, which was at one time printed amongst the writings of Placentinus, but has been properly reassigned to its true author by Cujacius, upon the internal evidence contained in the additions annexed to it, which are undoubtedly from the pen of Placentinus. Savigny considers this Commentary, which is the earliest extant work of its kind emanating from the school of the Gloss-writers, to be a model specimen of the excellence of the method introduced by Irnerius, and a striking example of the brilliant results which had been obtained iu a short space of time by a constant and exclusive study of the sources of law.