Please answer a question about the following article about Estonia:

After centuries of Danish, Swedish and German rule the native Estonians started to yearn for independence during the period of national awakening while being governed by the Russian Empire. Established on 24 February 1918, the Republic of Estonia came into existence towards the end of World War I. During World War II, Estonia was then occupied by the Soviet Union in 1940, then Nazi Germany a year later and again in 1944 establishing the Estonian Soviet Socialist Republic. In 1988, during the Singing Revolution, the Estonian SSR issued the Estonian Sovereignty Declaration to defy against the illegal Soviet rule. Estonia then restored its independence during the 1991 coup by the Soviets on the night of 20 August 1991.

What war ended as Estonia was born?
World War I