Mikhail Shein
Mikhail Borisovich Shein (Russian: Михаил Борисович Шеин, [ˈʂɛ.ɪn]) (late 1570s–1634) was a leading Russian general during the reign of Tsar Mikhail Romanov. Despite his tactical skills and successful military career, he ended up losing his army in a failed attempt to besiege Smolensk and being executed for this defeat. The first Russian generalissimo, Aleksey Shein, was his great grandson.
He left behind diaries, one of which is kept at the National Archives of Sweden, providing historical detail on the siege of Smolensk until his surrender in 1634.