In the Soviet era, all Russian flags were based on the Red Banner, which had its roots in the French Revolution and, possibly, even earlier peasant uprisings. After the formation of the Soviet Union, the official state flag contained a gold hammer, sickle, and gold-bordered red star in the upper hoist corner. When the Soviet Union dissolved, its symbols were replaced. The non-Russian territories acquired by tsars and communist leaders became independent, and the Russian Federation that remained readopted the white-blue-red Russian national flag. It became official on August 21, 1991, four months before the formal dissolution of the Soviet Union.