GLÜCKSTADT, a town of Prussia, in the province of Schleswig-Holstein, is situated on the right bank of the Elbe, -where it receives the small river Rhin, and on the railway from Itzehoe to Elmshorn, 28 miles N.W. of Altona. It has a Protestant and a Catholic church, a synagogue, a gymnasium, a provincial prison, and a provincial penitentiary. The inhabitants are chiefly engaged in commerce and fishing; but the frequent losses from inundations have greatly retarded the prosperity of the town. It suffers at the same time from a very deficient water supply for culinary purposes.

Gluckstadt was founded by Christian IV. of Denmark in 1616, and fortified in 1620. It was formerly the seat of the royal dukes of Schleswig-Holstein, who assumed from it the name of Holstein-Glückstadt. In 1627-8 it was besieged for fifteen weeks by Tilly, without success. In 1814 it was blockaded by the allies and capitulated, whereupon its fortifications were demolished. In 1830 it was made a free port. It came into the possession of Prussia along with the rest of Schleswig-Holstein in 1866. The population in 1875 was 5031.