Russian rulers have a long and complex history, beginning with the establishment of the Kievan Rus in the 9th century. Notable early rulers include Vladimir the Great, who adopted Christianity, and Yaroslav the Wise, known for his legal reforms. The Mongol invasion in the 13th century significantly impacted Russian governance, leading to the rise of the Grand Duchy of Moscow. In the 16th century, Ivan IV, also known as Ivan the Terrible, became the first crowned Tsar of Russia, expanding the territory. The Romanov dynasty, which began in 1613, ruled for over 300 years, culminating in the reign of Nicholas II, who was overthrown during the Russian Revolution in 1917.