In the meantime, the Russian Time of Troubles was far from over, and Russia had no strength to take advantage of the Commonwealth's weakness. On 21 February 1613 the Zemsky Sobor ("assembly of the land") named Michael Romanov, the now 16-year-old son of Fyodor Romanov, the new tsar. Fyodor, now installed as Patriarch Filaret, was a popular boyar and patriarch of Moscow, one of several boyars who vied to gain control of the Russian throne during the Time of Troubles. The Romanovs were a powerful boyar family; Michael's great-aunt (the sister of his grandfather) was Anastasia Romanovna, the wife of Ivan the Terrible. However, the new tsar had many opponents. Marina Mniszech tried until her death in 1614 to install her child as Tsar of Russia; various boyar factions still vied for power, trying to unseat the young Tsar Michael; and Sweden intervened in force, trying to gain the throne for Duke Carl Philip, even succeeding for a few months. However, Philip received even less support than Władysław, and the Swedes were soon forced to retreat from Russia.