The island of Sicily, which in the preceding century had been conquered by the Norman lords of Apulia and Calabria, then formed, together with a part of lower Italy, a kingdom which was under the control of the Holy See. Not many years before, under the reign of William I., the country had been in a prosperous condition, but now it was weakened by internal dissensions, and in no position to offer a successful defence to attacks from without. William II., surnamed the Good, had married Richard's sister Joan, who bore to him no children. Anxious to preserve the succession to his family, he caused his aunt, the Princess Constance, who was the only legitimate member of the family, to be married to Henry, son and heir of the Emperor Frederick Barbarossa. By securing to her a powerful husband, able to support her claims, the king trusted to overcome that opposition to a female sovereign which was likely to be even greater in Sicily than in other countries of Europe. Constance, at the age of thirty-two, was considerably older than her husband; but her dower was rich, and this, joined to the prospect of the succession, proved attraction sufficient for the young prince. He married her in the year 1186, at Milan. In November, 1189, William the Good died, appointing by his will that his aunt Constance should be his successor. The barons of the kingdom had previously taken an oath of fealty to the princess, but that oath, as well as the will of the king, was entirely disregarded. The nobles were necessarily indisposed to submit to the rule of a foreign prince, and the aggressions of the German emperors in the north of Italy had given good cause for dread of any further increase of their power. Constance and Henry were also out of the country at this critical moment, and the barons, after various disputes among themselves, conferred the crown upon Tancred, nephew to William the Good, though reputed to be illegitimate by birth. The new king was hailed by the people with acclamation, and was acknowledged by the Pope, Clement III., who sent him the customary benediction. His reign, however, had no sooner commenced, than various conspiracies were formed against him by the barons who had been competitors for the throne, and though he had succeeded in reducing these to submission, he was threatened by Henry, who had now become emperor, and who was preparing a powerful army to support the claims of his wife Constance.