Tsarist absolutism (Russian: Самодержавие) was a form of absolute monarchy specific to Tsardom of Russia and the Russian Empire. It's more despotic then the enlightened absolutism, as the ruler is not constrained by the laws (which he can change), but it is different from despotism, as the ruler is not seen as God.
[Peter the Great]] reduced the power of the nobility and strengthened the central power of the Tsar, establishing a bureaucracy and a police state. This was built on by Catherine the Great and other later Tsars. Although Alexander II made some reforms and established an independent judicial system, Russia did not have a representative assembly or a constitution until the 1905 Revolution.