The Treaty of Paris concluded on January 6, 1810, forced Sweden to join the Continental System, a trade embargo against Great Britain. Since Great Britain was Sweden's biggest trade partner this caused economic difficulties, and the trade continued to take place through smuggling. On November 13, 1810, France delivered an ultimatum to the Swedish government demanding that within five days Sweden: * Declare war against Great Britain, * Confiscate all British ships in Swedish ports, * Seize all British products in Sweden.