In the fifteenth century that part of the Seine comprehended within the enclosure of Paris contained five islands: the Ile Louviers, then covered with trees and now with timber, the Ile aux Vaches, and the Ile Notre Dame, both uninhabited and belonging to the bishop [in the seventeenth century these two islands were converted into one, which has been built upon and is now called the Isle of St. Louis]; lastly the City, and at its point the islet of the Passeur aux Vaches, since buried under the platform of the Pont Neuf. The City had at that time five bridges: three on the right--the bridge of Notre Dame and the Pont au Change of stone, and the Pont aux Meuniers of wood; two on the left--the Petit Pont of stone, and the Pont St. Michel of wood; all of them covered with houses. The university had six gates, built by Philip Augustus; these were, setting out from the Tournelle, the Gate of St. Victor, the Gate of Bordelle, the Papal Gate, and the gates of St. Jacques, St. Michel, and St. Germain. The Ville had six gates, built by Charles V, that is to say, beginning from the Tower of Billy, the gates of St. Antoine, the Temple, St. Martin, St. Denis, Montmartre, and St. Honoré. All these gates were strong, and handsome, too, a circumstance which does not detract from strength. A wide, deep ditch, supplied by the Seine with water, which was swollen by the floods of winter to a running stream, encircled the foot of the wall all round Paris. At night the gates were closed, the river was barred at the two extremities of the city by stout iron chains, and Paris slept in quiet.