Was Estonia ever a part of another country?

Estonia has been a part of several other countries throughout its history. Here are a few examples:

1. Swedish Rule: From the 13th to the 16th century, Estonia was under the rule of Sweden. During this time, it was known as the Duchy of Estonia.

2. Polish-Lithuanian Commonwealth: In the 16th century, Estonia became part of the Polish-Lithuanian Commonwealth. It remained under their control until the 18th century.

3. Russian Empire: In the 18th century, Estonia was annexed by the Russian Empire and remained a part of it until the Russian Revolution in 1917.

4. Part of the Soviet Union: After the Russian Revolution, Estonia became a part of the newly formed Soviet Union. It remained a Soviet Socialist Republic until the collapse of the Soviet Union in 1991.

Since regaining its independence in 1991, Estonia has been a sovereign nation and is currently a member of the European Union and NATO.