This “sea” originated as the consequence of several heavy storms that transformed the Flevomeer, or Almere, into an open arm of the North Sea sometime between 1500 B.C. and the Ro man period. The first mention of the name Zuiderzee is in a 13th century document. Many harbor towns were built along its coasts, among them Amsterdam, Hoorn, and Enkhuizen. From 1928 to 1932, a 30-kilometer-long (19-mile) dam called the Afsluitdijk was constructed, closing off the Zuiderzee, which has been called the IJs selmeer since then. Several major projects of land reclamationwere realized: the Wieringermeerpolder in 1934 (inundated by Nazi Ger many in 1945), the Noordoostpolder in 1942, and the Flevopolders in 1957–1968. The harbor of Amsterdam has had a new connection with the North Sea since 1865–1876, the North Sea Canal. Recently, Amsterdam set up a new town district in the IJsselmeer: IJburg.
See also Flevoland.
Historical Dictionary of the Netherlands. EdwART. 2012.