After the end of the Opium Wars in China, East Asia became the conflict zone of strategic interests and competing imperialism of the great European nations, as well as the United States and Japan. Russian researcher Anatoly V. Remnev wrote in the early 2000s: “One of the most important features of the functioning of regional power in Asian Russia of the XIX – early XX centuries was the lack of a clear boundary between foreign and domestic policies and the incompleteness of the process of formalisation of the state borders” (Remnev, 2004, p. 20). Sergey Glebov notes, “The very term “Far East” is of relatively late progeny. Although the term was used in reference to China and Japan beginning in the 1880s, it emerges as a reference to the Russian provinces only at the turn of the twentieth century, most likely as a calque from the French l’Orient Extrême around the time of the Boxer Rebellion” (Glebov, 2019, p. 267). Since the second half of the nineteenth century, colonisation of the Russian East Asia became a priority for the Russian Empire. In addressing that priority, the government had to face a number of well-known difficulties: harsh weather conditions, sparse density of population, and underdeveloped transport infrastructure. The goal of this chapter is to characterise for English-speaking readers the voluminous collections of official documents, eyewitness evidence preserved in Russian archives on competing imperialism in connection with Russian policy, and colonisation activity in the Far East in the early twentieth century.