Answer
Contrary to the popular belief, Kārlis Ulmanis was never imprisoned during his political career. He, in fact, was elected as the Prime Minister of Latvia four times and served in that role from 1918 to 1920 and again from 1931 to 1940. During his second term as Prime Minister, he staged a self-coup, establishing an authoritarian regime that lasted until the Soviet occupation of Latvia in 1940.