While these female feuds were threatening Muley Abul Hassan with trouble and disaster at home, his evil genius prompted him to an enterprise which involved him in tenfold danger from abroad. The reader has already been apprised of a singular clause in the truce existing between the Christians and the Moors, permitting hasty dashes into each other’s territories and assaults of towns and fortresses, provided they were carried on as mere forays and without the parade of regular warfare. A long time had elapsed, however, without any incursion of the kind on the part of the Moors, and the Christian towns on the frontiers had, in consequence, fallen into a state of the most negligent security. In an unlucky moment Muley Abul Hassan was tempted to one of these forays by learning that the fortress of Zahara, on the frontier between Ronda and Medina Sidonia, was but feebly garrisoned and scantily supplied, and that its alcayde was careless of his charge. This important post was built on the crest of a rocky mountain, with a strong castle perched above it upon a cliff, so high that it was said to be above the flight of birds or drift of clouds. The streets and many of the houses were mere excavations wrought out of the living rock. The town had but one gate, opening to the west and defended by towers and bulwarks. The only ascent to this cragged fortress was by roads cut in the rock, so rugged in many places as to resemble broken stairs. In a word, the impregnable security of Zahara had become so proverbial throughout Spain that a woman of forbidding and inaccessible virtue was called a Zaharena. But the strongest fortress and sternest virtue have weak points, and require unremitting vigilance to guard them: let warrior and dame take warning from the fate of Zahara. CHAPTER IV. EXPEDITION OF MULEY ABUL HASSAN AGAINST THE FORTRESS OF ZAHARA.