Nikolai Ivanovich Lorer (1797–c. 1873) was a Russian army officer and member of the Decembrist secret society who, following the failed uprising of 1825, was exiled to Siberia and subsequently forced to serve as a common soldier in Russia's Caucasian campaigns. Between 1837 and 1841 he participated in military expeditions along the eastern Black Sea coast against Circassian tribes including the Shapsug and Ubykh. 

His memoir, Zapiski Dekrabrista ("Notes of a Decembrist"), first published in full in Moscow in 1931, is among the most candid firsthand Russian accounts of the conquest of the Caucasus — and one of the very few in which a serving Russian officer openly questions the moral legitimacy of that conquest. The memoir documents Russian atrocities against Circassians with striking specificity. Lorer records General Zass's explicit admission that burning Circassian villages, plundering, and summary hangings were not aberrations but deliberate imperial doctrine — invoking Ermolov's terror campaigns as the model to follow (p. 247–248). He describes the permanent display of severed Circassian heads on pikes at the Prochny Okop garrison, and Zass's private collection of boiled skulls dispatched to anatomical institutes in Berlin (p. 247–248). He witnesses the massacre of retreating Ubykh fighters — "cut and bayoneted without mercy" — following a naval landing on the Black Sea coast (p. 227–228), and records the systematic seizure of Circassian food stores under the justification that "war has its rights" (p. 205–206). 

What sets this source apart is Lorer's refusal to simply celebrate what he witnessed. On page 214 he asks — in a passage suppressed by tsarist censors and restored only in this 1931 edition — "Fire and the sword will bring no benefit: who gave us the right to bring civilization in this manner to people who are content with their freedom and their property?" For researchers and curators of the Circassian Genocide, Notes of a Decembrist is an indispensable primary source: a Russian military insider's testimony that documents specific acts of mass violence and occasionally breaks into open moral protest.