Mikhail Borisovich Shein (?–1634) was a Russian warlord of Tsar Mikhail Romanov. Despite his tactical skills and successful military career, he ended up losing his army at the Siege of Smolensk. He was accused of treason and incompetence after this defeat, and executed.
Shein was fully conversant with the Russian army's need to modernize. He was content to have up-timer Cass Lowry as military advisor for the "Gun Shop".
Shein was almost executed during the purges that followed Fedor Ivanovich Sheremetev's takeover. Instead, he was demoted and placed in charge of one section of the Siberian frontier, about as far from Moscow as he could be while still being in Russia.