Originally, the province Bohusl�n, where Str�mstad is situated, was Norwegian territory, which was transferred to Sweden according to the Treaty of Roskilde in 1658.
At Str�mstad, there was a small fishing village known as Str�mmen. The town got small privileges as a merchant town (k�ping) shortly thereafter, which seems to have made it expand, because it is documented to have gotten a charter in 1676 by King Charles XI of Sweden, although some documents show it was already considered a city in 1672. As it was the seat for a merchant navy, the coat of arms was designed with such a ship, and has remained that way even after the use of sailing ships was discontinued in the 19th century.
The city was a seat for Sweden's warfare against the Danish-Norway, and more than once it was conquered and reconquered throughout the centuries. The warlike King Charles XII of Sweden, for instance, used it as his outpost for his campaign against Norway in 1716�1718.
At the time it had a population of 300 inhabitants. But soon the fishing blossomed, and its population increased to 1,100 by 1805. The late 18th century also saw the spa and bathing attract visitors, a position it kept throughout the 19th century. By 1917, its population was 2,949 inhabitants
