Excerpts from Books and Wikipedia
"The Time of Troubles (Russian) was a period of Russian history comprising the years of interregnum between the death of the last Russian Tsar of the Rurik Dynasty, Feodor Ivanovich, in 1598, and the establishment of the Romanov Dynasty in 1613. In 1601–03, Russia suffered a famine that killed one-third of the population, about two million. At the time, during the Polish–Muscovite War (1605–18) (known as the Dimitriads), Russia was occupied by the Polish–Lithuanian Commonwealth, and suffered from civil uprisings, usurpers and impostors." [Wikipedia]