On the south side of the Patio de los Leones is the Sala de los Abencerrages (Hall of the Beni Serraj), so called because it is believed to be the scene of the massacre of thirty-six chiefs of that tribe by order of Boabdil. A reddish vein in the marble flooring is pointed out as the victims’ indelible bloodstains. The story has only the slenderest historical foundation, and was first circulated by a writer of the name of Ginés Perez de Hita, who lived in the sixteenth century. According to some, the usurper Aben Osmin (1446) was beheaded here by order of the prince Muley Hassan; but others, writing of that confused period of Granadine history, say the tyrant fled to the mountains. This chamber, perhaps the most elegant in the Alhambra, does not seem a likely place for deeds of blood. It is entered through a wonderfully graceful arch, growing out of, rather than springing from, marble shafts. The chamber is a square, prolonged on the east and west by two _alhamis_ or alcoves, which are entered through exquisitely-curved arches. But the glory of the Sala de los Abencerrages is its roof--its plan like that of a star, with pendants or stalactites, and sixteen windows in its vaultings. “Its thousand stalactites,” writes Don Francisco Pi Margall, “its colours, its innumerable archings, its crowns of stars, its complicated depressions and projections, its cones, its polygons, its accidents of light, the effects of chiaroscuro, present it at first sight as something confused, indefinable, indecipherable, resplendent, and vague, like that broad band, the Milky Way, which crosses the pavilion of the heavens. Yet in reality it is most regular, although irregular in appearance; the compass of the geometrician had more to do in planning it than the genius of the artist; but its lines are so many, and their combinations change so rapidly, that the scheme is only to be comprehended after a long and patient study.” The azulejos which face the walls date from the time of Charles V. In the centre of the hall is the marble basin beside which the Beni Serraj are fabled to have been slain.