Russian culture has been influenced by Orthodox Christianity, with many spectacular churches built since Kievan Rus' adopted Christianity in 988. Russia has a history of innovation, being the first to send satellites and humans into space during the Soviet era. There are eight public holidays celebrated in Russia, with New Year's Day being the most popular and celebrated similarly to Christmas in Western cultures. Victory Day on May 9 commemorates the defeat of Nazi Germany in World War 2 with an annual military parade.