The danger which had threatened the Moorish dominions on the northern side having been disposed of, Motamid, elated by the distinction he had gained at the battle of Zallaca, determined to attempt the expulsion of the Christians from Eastern Spain. This, as he was well aware, would prove no easy undertaking. The provinces of Valencia and Murcia were at that time controlled by the most formidable bands of mercenaries, adventurers, and outlaws in Europe. The principal seat of this military banditti was Aledo, a fortress occupying the summit of an isolated mountain, and whose defences, natural and artificial, were supposed to be proof against the utmost skill of the mediæval engineer. Here were conveyed indiscriminately the sacrilegious plunder of mosques and churches, the hard-earned possessions of the husbandman, the enslaved peasantry of the Valencian and Murcian villages, and the beautiful female captives of Andalusia. The robbers domiciled in this fortress served under Castilian officers and were nominally Christians, but their allegiance to both creed and crown was precarious; destitute of faith, religion, or loyalty they were composed of the dregs of every nation, and even many renegade Moslems were enlisted in their ranks. The garrison of Aledo could muster thirteen thousand fighting men. The victory of Zallaca, whose consequences were not permanent even in the region where it had been obtained, had in nowise affected the distant provinces of Eastern Spain. The Moorish population were daily more and more harassed by raids and enforced contributions; the inhabitants of the most fertile districts were greatly diminished in numbers by violence and flight; and it was evident that erelong the feeble remnant of the industrious race which had transformed that portion of the Peninsula into a paradise must be either enslaved or exterminated by the outlaws of Valencia and Aledo. Motamid, whose meritorious intention to avenge the injuries of the Arabs of the eastern principalities was further justified by the fact that Lorca and Murcia both owed him allegiance--the one by right of inheritance, the other by the title of voluntary submission--and could consequently demand his protection, having assembled his army, which included the Almoravides whom Yusuf had placed under his command, began his march towards Murcia.