When was Latvia founded?

Latvia was first declared a sovereign state, the Republic of Latvia, on November 18 1918. From 1940 through to the end of World War II, Latvia was occupied first by forces of the Soviet Union, then Nazi Germany and, at the end of the war, was again under Soviet occupation.
The second Soviet occupation continued until the 1991, when Latvia was able to use the break up of the Soviet Union to re establish its independence.