After Estonia’s long and ancient history that included Viking and Teutonic influence, in 1629, Sweden took control of mainland Estonia.
In 1710, Russia forced Sweden to hand over Estonia as a part of the Treaty of Nystad.
In 1918, after the Bolshevik Revolution, Estonia gained independence from Russia only to lose it again to the Soviets then, in 1941, to the Germans.
In 1944, Soviet forces again took control of Estonia.
Decades later, a large majority of western countries declared that Soviet occupation of Estonia was illegal and Estonia finally declared independence, again, on 20 August 1991.