JUEL, NIELS (1629-1697), Danish admiral, was born of a distinguished family on May 8, 1629, at Christiania. He served his naval apprenticeship under Van Tromp and De Ruyter, taking part in all the chief engagements of the war of 1652-54 between England and Holland. During a long indisposition at Amsterdam in 1655-1656 he acquired an excellent knowledge of ship-building, and returned to Denmark in 1656 a thoroughly equipped seaman. He served with distinction during the Swedo-Danish wars of 1658-6o and took a prominent part in the defence of Copenhagen against Charles X. During fifteen years of peace, Juel, as admiral of the fleet, improved the Danish navy, though he bitterly re sented the setting over his head in 1663 of Cort Adelaar on his return from the Turkish wars. On the outbreak of the Scanian War he served at first under Adelaar, but on the death of the latter in November 1675 was appointed to the supreme com mand. He raised Danish sea-power to unprecedented eminence, by the system of naval tactics, afterwards perfected by Nelson, which consists in cutting off a part of the enemy's force and con centrating the whole attack on it. He first employed this ma noeuvre at the battle of Jasmund off Riigen (May 25, 1676) when he broke through the enemy's line in close column and cut off five of their ships. A few days after the battle of Jasmund, Cornelius Van Tromp the younger, with 17 fresh Danish and Dutch ships of the line, superseded Juel in the supreme command.
Juel took a leading part in Van Tromp's great victory off Oland (June I, 1676), which enabled the Danes to invade Scania unopposed. On June 1, 1677 Juel defeated the Swedish admiral Sjoblad off MOen ; on June 3o, 1677 he won his greatest victory, in the Bay of Kjoge, where, with 25 ships of the line and 1,267 guns, he routed the Swedish admiral Evert Horn with 36 ships of the line and 1,800 guns. For this great triumph he was made lieutenant admiral general and a privy councillor. This victory, besides permanently crippling the Swedish navy, gave the Danes a self-confidence which enabled them to keep their Dutch allies in their proper place. In the following year Van Tromp, whose high-handedness had become unbearable, was discharged by Christian V., who gave the supreme command to Juel. In the spring of 1678 Juel put to sea with 84 ships carrying 2,400 cannon, but as the Swedes did not venture out to sea, his operations were limited to blockading the Swedish ports and transporting troops to Riigen. After the peace of Lund Juel devoted himself to the development of the fleet. He died on April 8, 1697.
See Garde, Niels _fuel (1842), and Den dansk. norske SOmagts His torie, 15j5-1700 (1861).