The ambition of Pedro was insatiable; but it was also senseless, as it grasped at impossibilities. Hearing that some people of Athens and Patras, who were of Aragonese extraction--the descendants of the crusaders, who had conquered this duchy--had risen to establish his domination, he sent an armament to their aid, and was ultimately acknowledged. It need, however, be scarcely observed that possessions so far removed from the seat of power would yield but a nominal allegiance, and would soon be lost. But there was no advantage, however small in magnitude or transient in duration, which he was not at all times ready to grasp--generally without much regard to the rights or feelings of others. The avidity with which, in 1386, he seized on the city of Tarragona, the government and sovereignty of which had long rested with the archbishops of that see, is affirmed by some historians to have been the cause of his death.[42] He died early in the month of January, 1387, after an agitated reign of fifty-one years. The duplicity of this monarch was only equalled by his violence; of sincerity and justice he was wholly destitute; and in savage barbarity he was scarcely exceeded by his namesake of Castile. With many of the vices and none of the virtues of humanity, he was neither loved nor respected; but, in return, he was feared. It is impossible not to admire his constancy in reverses: he deviated not from his purposes, nor suffered his mind to be depressed, in the most critical periods of his reign--and few princes were ever placed in circumstances more critical--yet he almost uniformly gained his end. Justice must also allow that, whatever were his personal vices, he was no enemy to the lowest class of his people. During the reign of this prince, the era of Cæsar was abolished, and the Christian adopted for the two chief kingdoms of Spain; in 1350 at Saragossa, and in 1383 at Segovia.[c] Pedro IV enlarged the powers of the justiciary, enabling him to oppose his veto to usurpations on the part of the crown in the same way as to the encroachments of the feudal aristocracy; he provided for the swift and careful administration of justice; promoted the study of law, and showed favour to the legal and juridical profession. Whenever occasion offered and he was not prevented by the inhibitory intercession or legal warrant of the justiciary, he curbed the usurpations and arbitrary action of the great nobles and increased the privileges and power of the knights and burghers.[b] [Sidenote: [1387-1408 A.D.]]