[edit]
Frederikshavn was originally called Fladstrand (lit. "Flat beach") from its location in Flade parish.: 5–6 
Historical populationYearPop.±% p.a. 1696 565—     1715 788+1.77% 1769 525−0.75% 1801 463−0.39% 1818 600+1.54% 1834 1,163+4.22% 1840 1,247+1.17% 1845 1,332+1.33% 1850 1,374+0.62% 1855 1,467+1.32% 1860 1,843+4.67% 1870 2,133+1.47% 1880 2,891+3.09% 1890 4,848+5.31% 1901 6,538+2.76% 1911 7,916+1.93% 1916 8,560+1.58% 1921 9,411+1.91% 1925 9,650+0.63% 1930 9,882+0.48% 1935 10,500+1.22% 1940 15,275+7.79% 1945 16,827+1.95% 1950 18,388+1.79% 1955 20,212+1.91% 1960 22,570+2.23% 1965 24,379+1.55% 1970 24,848+0.38% 1976 25,316+0.31% 1981 24,938−0.30% 1986 25,137+0.16% 1990 25,137+0.00% 1996 24,935−0.13% 2000 24,680−0.26% 2006 23,636−0.72% 2010 23,331−0.32% 2015 23,345+0.01% 2020 23,124−0.19%Source: 1696,: 37 1715,: 40 1769,: 95 1801,: 95 1818-1845,: 96 1850,: 96 1855-1860,: 96 1870—1916,: 76 1921—1950,: 81 1950-1970,: 83 1976—2000, 2006, 2010—
Fladstrand[edit]
The first mention of a settlement is in a letter dated 13 March 1572 found in the Danish chancery letterbooks.: 5  It was a fishing village, trading place and crossing point to Norway.: 95 
The old Fladstrand church was built between 1686 and 1690.: 7  On 31 December 1700 a tax of 500 rigsdaler was put on the town which indicates a fair amount of trade.: 8–9 
During the Great Nordic War from 1700 to 1721 the town saw a rise in activity as travellers to Norway embarked from here as the route over Sweden was cut. The activity slowly subsided after the war.: 12 
A royal maritime pilot was stationed at the town from 1733 after King Christian VI was forced to stay in the town due to bad weather on his journey to Norway.: 9–10 
In 1735 the town was described as a hamlet which supports itself on fishing and beaching of scows and some farming (fæstebønder).: 11–12 
Military history in 17th, 18th and 19th centuries[edit]
Due to its advantageous proximity to the entrance to the Baltic Sea, Frederikshavn has historically been a naval base of some strategic importance.
In 1627 under Kejserkrigen, Melchior von Hatzfeldt troops built a Sconce north of the fishing village.: 95  The sconce became known as Nordre Skanse and is preserved to this day. After the war this was manned by Danish troops.: 95  In 1675 the fortification was expanded with a sconse south of the harbour.: 95  Between 1686 and 1687 the fortification was expanded again with a heavy tower, a wall and a port. It was described as a citadel. The tower is known as Krudttårnet, (lit. "Gunpowder Tower"). In 1891 the wall and port was demolished, but the tower has been preserved.: 95  Krudttårnet is incorporated in the municipality's coat-of-arms.
During the Great Nordic War from 1700 to 1721 Peter Tordenskjold barricaded himself here in his fights against Sweden.: 95  In 1712 the Battle of Fladstrand was fought in the nearby sea between Swedish and Danish naval forces.[citation needed]
In 1735, 50 Danish men were stationed at the fortress.: 11–12  From the middle of the 18th century the military importance of the citadel was dwindling and some of the fortifications and building was disposed of. It gained new importance during the Gunboat War from 1807 to 1814, but its value diminished again after the war. The citadel was discontinued in 1864.: 95 
Market town[edit]
During the Gunboat War, the town saw increasing trade and activity. The first artificial harbour was constructed from 1808 to 1810 due to the war and after several years of strong promotion of the local merchant Frantz Übersax.
Denmark's defeat in the war had a great impact in Fladstrand. The military left and the town largest source of income ceased.: 56–57  Denmark's general economic crisis worsened the situation.: 56–57  The town did not have status as a market town, but trade, craft and other activities exclusive to market towns had happened unlawful in Fladstrand for several decades anyway.: 52–54, 61  A majority of the population had livelihoods based on crafts, services and trade, not production. This was used by the local civil servant as an argument for giving the town market town status (Danish: købstadsrettigheder).: 61–62  The harbour directorate (Danish: Kanal-, havne- og fyrdirektionen) argued that it was a strategic place for a harbour and giving the town market town status and legalising the current activities would help with the upkeep.: 62–63 
On 25 September 1818 Frederik VI bestowed the town status as a market town under the name of Frederikshavn.: 63–64 
From 1818[edit]
During the 1970s the ship yard wanted to expand with a dry dock at the location of Krudttårnet. Between 1974 and 1976 the engineering firm Kampsax and the local contractor Trigon encased the tower in concrete and moved it 270m along teflon rails to its current location. The project was delayed when a storm broke a retaining wall between Christmas and New Year 1975 filling the new dry dock with water and causing the base beneath the tower to collapse.: 222  The movement was celebrated 5. August 1976 with the visit from Margrethe II of Denmark and her family.: 221 
Stena Line operated a ferry service from Frederikshavn to Oslo, Norway from 1979 to March 14, 2020. It was served by three different ferries named Stena Saga. From 1979 to 1988 by former M/S Patricia built in 1967. From 1988 to 1994 by later MS Stena Europe. From 1994 to 2020 it was served by MS Stena Saga. It was first closed temporary due to the coronavirus pandemic. The decision to close it permanently was announced a few days later on March 19. The Oslo route was reopened by DFDS Seaways on June 25, 2020 by the ferries traveling to and from Copenhagen which began stopping in Frederikshavn. There is a single departure and arrival per day. The route is serviced by MS Pearl Seaways and MS Crown Seaways.[needs update]
