Lomonosov was one of Russia’s greatest scientists, though in his time was mainly known as a writer: a true polymath, he published work in physics, chemistry, geology, astronomy, classics, language and history, largely working alone. Wolff influentially taught him in Germany. He became Euler’s assistant and later his close colleague in St Petersburg; they corresponded until Lomonosov’s death. He stood as guarantor for his friend and colleague Gmelin, who defaulted (Euler intervened, Gmelin paid him back). He warmly supported Müller’s explorations in Siberia, but (both were hot-headed) took violently against his theory of a Norse origin for the Russian nation.