The term 'Russian Ruler's Domain' can be summarized as Tsardom, which is a 7-letter word. Tsardom was the term used to refer to the autocratic rule of the Tsar in Russia from the 16th century until the Russian Revolution of 1917. The Tsar was the absolute ruler of the Russian Empire and had complete control over the government and its people. Tsardom was characterized by a strong central government, a powerful military, and a strict social hierarchy.