Trondhjem, or THRONDHJEM, a town of Norway, at the mouth of the Nid, on the south shore of the Trondhjem Fjord, 250 miles north of Christiania by railway. The streets are broad and regular, with well-built houses, mostly of wood. The cathedral, dating chiefly from the l2th and 13th centuries, was almost wholly destroyed by a succession of fires, but it has recently been restored; it is the place of coronation of the kings of Norway. Copper ore, timber, oil, and salt fish are exported. Trondhjem, originally Nidaros, was founded by Olaf Tryggvason in 996.