Martinus Polonus (also Martin von Troppau, Martinus Oppaviensis, and Martin z Opavy) was a Dominican monk in the 13th century, whose home monastery was probably in Troppau (Czech: Opava). This accounts for the often used descriptive surname "von Troppau," whereas the surname "Polonus" indicates his home monastery which belonged to the Polish province of the Dominican Order. The scarce biographical information on the Dominican monk Martinus comes mostly from his own writings. There exists no information on the birthdate or birthplace of Martinus, but according to the Dominican monk Hyacinth of Prague, he was ordained in Prague after his education at the preacher monastery there. He later successfully worked for the advancement of his home monastery at the pontifical court, where during the papacy of Alexander IV (1261-1278), he had a position there as poenitentiarius minor. On June 22, 1278, Martinus was appointed Archbishop of Gnesen by Alexander IV's successor, Nicolaus III, though he died in Bologna while on the return trip to his church province in Poland. For modern historical studies, Martinus is one of the most respected chroniclers of the Middle Ages, and his importance lies in the writings he left behind. Besides a collection of ecclesiastical sources, the "Tabula Martiniana Decreti," and a collection of sample homiletic pieces, the "Sermones de tempore, de sanctis," his work "Chronicon pontificum et imperatorum," a chronicle of the popes and emperors up until Pope Nicolaus III contained in 500 manuscripts, is regarded as the most important work of the so-called chronicles of the mendicant orders.