Leyden, one of the chief towns of Holland, stands on the Rhine a few miles from its mouth, about midway between Haarlem and Rotterdam, and 15 miles N.W. of the Hague. In the Middle Ages it was celebrated for its cloth manufacture, but saw troublous times, being six times during the 15th century besieged by the "Hooks." During the War of Independence it held out from October, 1573, to the same month in 1574; and the inhabitants were rewarded for their heroism by the establishment of a university which was to take a high place in the learned world. Medicine and law have perhaps been its most prominent faculties, but theology and classical learning also had their place. Amongst alumni and professors have been Grotius, Descartes, Scaliger, Salmasius, Sir Thomas Browne, Alexander Monro, and recently Kuenen and Cobet; while Linnaeus and Boerhaave have been among the directors of the celebrated botanic gardens. The university possesses a fine collection of Greek and Oriental MSS., a fine natural history museum, a museum of antiquities especially rich in its Egyptian department, and an ethnographical museum containing Von Siebold's Japanese collection. It has now somewhat diminished in importance, but has still fifty professors and some 800 students. Rembrandt, Jan van Steen and Gerard Douw were natives of the places, as also were some of the Elzevirs. The "Burg," a round wall resting upon arches on a mound in the centre of the town, is said to be of Roman origin; the town hall dates from the 16th century. The church of St. Pancratius has a monument to Van der Werf, the hero of the siege, and that of St. Peter contains memorials of Scaliger, Arminius, and Boerhaave. The chief modern institution of Leyden is its school of navigation. An open space on the south of the town commemorates by its name, "The Ruin," an explosion by which in 1807 a large part of Leyden was destroyed. After the seventeenth century its population and trade began to decline, and they have never since materially increased.