Don Pedro announced publicly, before the assembled cortes at Seville, that his marriage with Blanche of Bourbon had been illegal, inasmuch as he had been previously married to Maria de Padilla. He called witnesses, among them a few of the clergy, and these confirmed his statement on oath. Through the murder of Blanche, and its consequences, an opportunity offered itself to Don Henry de Trastamara to obtain allies for the dethronement of the king, and of this he was not slow to avail himself. The Bourbons in France and the king promised him aid, and allowed him to enlist the wild lances of the so-called great or white company, who, at the conclusion of the war with England, were rendering France insecure. The pope, displeased at the favors shown by Don Pedro to the Jews, also supported Don Henry, and placed the king of Spain under the ban.
To invest his rebellion with a tinge of legality and win the feelings of the people, Don Henry blackened his brother's character, picturing him as an outcast who had forfeited the crown because he had allowed his states to be governed by Jews, and had himself become attached to them and their religion. Don Henry carried his calumnies so far as to state that not only his mistress, Maria de Padilla, was a Jewess, but that Don Pedro himself was of Jewish extraction.
With the mercenaries of the "white company," graceless banditti, Henry crossed the Pyrenees to make war on and, if possible, depose his brother. At the head of these French and English outlaws stood the foremost warrior of his time, the hero and knight-errant, Bertrand du Guesclin (Claquin), celebrated for his deeds of daring, his ugliness, and his eccentricity, who, like the Cid, has been glorified by legend. The Jews consistently cast in their fortunes with those of the Don Pedro party, and supported it with their money and their blood. They flocked to its standard in the field, and garrisoned the towns against the onslaughts of Don Henry and Du Guesclin. The wild mercenaries to whom they were opposed avenged themselves not only on the Jewish soldiers, but also on those who had not borne arms.
The approach of the enemy compelled Don Pedro to abandon Burgos, the capital of Old Castile, and at an assembly of the inhabitants it was prudently resolved not to contest Don Henry's entrance. On taking possession of the town, where he was first proclaimed king (March, 1360), Henry levied a fine of 50,000 doubloons on the Jewish community, and canceled all outstanding debts due from Christians to Jews. The Jews of Burgos, unable to pay this large contribution, were compelled to sell their goods and chattels, even the ornaments on the scrolls of the Law. Those who could not make up their share of the contribution were sold into slavery. The whole of Spain fell to the conqueror in consequence of Don Pedro's neglect to concentrate round himself that portion of the population on which he could rely, or to buy over the free lances of the "white company," as he had been advised. The gates of Toledo, the capital, were opened to the victor, although Don Pedro's party, to which the Jews belonged, strongly counseled defense. Upon the Toledo community Don Henry also levied a heavy fine for its fidelity to the legitimate king. Don Pedro's last refuge was Seville, which he also lost.