In the middle ages some curious but not very clearly chronicled instances of these troublesome personages appear. A mysterious case occurred in Sicily in the twelfth century. Roger the Third, dying in 1149, was succeeded by his brother, William the Fourth; and when he expired, in 1186, a man came forward and claimed the crown, under the pretext that he was son of the former monarch. Eventually he was overthrown, and the throne left to the possession of Tancred, the legitimate heir. In 1570 there was an insurrection against the existing imperial rule in Russia that nearly met with success, and in which one of these pretenders to royalty played an important part. The rebels were led by Stenko, a Cossack chief, and at one time gained such advantages that the entire overthrow of the Romanoff dynasty appeared probable. Alexis, the reigning Czar, had recently lost his eldest son, the heir-apparent, towards whom his feelings were believed to have been anything but paternal. Availing himself of these circumstances, Stenko proclaimed that the Czarewitch was not dead, but had fled to his camp in order to seek refuge from his father's cruelty. A young Circassian, so it is alleged, was employed to personate the prince, whilst another representative was found to personify Nikon, the late patriarch of the Russian Church, who had been deposed and imprisoned by the Czar. The imposture was immensely successful for a time, as multitudes of the High Church party joined the rebels, whose numbers ultimately exceeded one hundred thousand men. Their triumph, however, was but transient, as they were entirely routed by the Imperial troops, whose taste for blood was gratified by the massacre of several thousands of the rebels, among whom, it is presumed, was the personator of the deceased Czarewitch.