ADELAER or ADELER, the surname given to KURT SIVERT SEN (1622-75), Norwegian-Danish sailor. Born at Brevig, in Norway, he entered the Dutch navy and then the Venetian serv ice, where he was known as Curzio Suffrido Adelborst (i.e., Dutch for "naval cadet"). He commanded the Venetian squadron at the battle of the Dardanelles (May 13, 1654) when his ship alone sank 15 Turkish galleys and burned others. Next day he compelled the surrender of the Turks at Tenedos.
In 1660 he became admiral-lieutenant in the Venetian service, but in 1662 he was induced to take command of the Danish fleet. Under Christian V. he took command of the combined Danish fleets against Sweden, but he died suddenly before the expedition set out.