Horse and rider,"MO" monogram (for "Moscow") below / Cyrillic inscriptions in 6 lines: "TSAR I VELIKIY KNYAZ ALEXEY MICHAILOVICH VSEYA RUSI" ("Tsar and Grand Duke Alexey Michailovich of All Russia"). 11mmx11mm, 0.34 grams. Moscow mint. Grishin #918.
Aleksey Mikhailovich was the Tsar of Russia during some of the most eventful decades of the mid-17th century. His reign saw the Russian invasion of Poland and war with Sweden during the Deluge, the Raskol schism in the Russian Orthodox Church, and the Cossack revolt of Stenka Razin. Aleksey was also the father of the future Tsar Peter the Great.