Horse and rider, mintmark oM below / Cyrillic inscriptions in 5 lines: "TSAR I VELIKIY KNYAZ BORIS FEYODOROVICH VSEYA RUSI" ("Tsar and Grand Duke Boris Fyodorovich of All Russia"). 15mmx11mm, 0.65 grams. Moscow mint, issued 1599. Grishin #163.
Boris Fyodorovich Godunov c. 1551 23 April [O.S. 13 April] 1605) was de facto regent of Russia from c. 1585 to 1598 and then the first non-Rurikid tsar from 1598 to 1605. The end of his reign saw Russia descend into the Time of Troubles.