While still only a boy of twelve in the palace in Berlin, Frederick the Great had been reminded by his father's anger and sorrow that the kings of Prussia had a duty as protectors toward the German colonies on the Vistula. For in 1724 a loud call from that quarter for help had rung through Germany, and the bloody tragedy at Thorn became an important subject of public interest and of diplomacy. During a procession which the Jesuits were conducting through the city, some Polish nobles of the Jesuit college had insulted some citizens and schoolboys, and the angered populace had broken into the Jesuit school and college and inflicted damage. This petty street-riot had been brought up in the Polish parliament, sitting as a trial court, and the parliament, after a passionate speech by the leader of the Jesuits, had condemned to death the two burgomasters of the city and sixteen citizens; whereupon the Jesuit party hastened to put to death the head burgomaster, Rössner, and nine citizens, in some cases with barbarous cruelty. The church of St. Mary was taken from the Protestants, the clergymen driven out, and the school closed. King Frederick William had tried in vain at the time to help the unfortunate city. He had prevailed upon all the neighboring powers to send stern notes, and had felt himself bitterly grieved and humiliated when all his representations were disregarded; now after fifty years his son came to put an end to this barbarous disorder, and to unite again with Prussia this land which before the Polish sovereignty had belonged to the Teutonic order. [Illustration: FREDERICK THE GREAT ON A PLEASURE TRIP _From the Painting by Adolph von Menzel_]