a very important fortress of Germany, seated on the banks of the Rhine, built by the French after a design of marshal Vauban, for the defence of Strasbourg. It was ceded to the empire in 1697, by the treaty of Ryswick. The French retook it in 1703, and it was restored to the empire by the treaty of Rastadt. E. Long. 7° 45', N. Lat. 48° 40'.