Orthodoxy, Autocracy, and Nationality were three main ideas in Russian society during the 1800s.
Orthodoxy was the idea that the church was the most important part of Russian society, and that loyalty to the church was necessary for success.
Autocracy was the idea that there should only be one leader in Russian society, the Tsar. The Tsar held all the power in the country, and was like a King or a Queen.
Nationality was the idea that Russians should be loyal to their own nation, and not to any other countries or people. People believed that each nation had its own unique culture, so it was important to stay loyal to Russian culture.