Six years later, he was summoned by boyars of Halych to rule their city but could not effectively claim the throne.
In 1215, he accepted the offer of the Novgorodians to become their prince but, desiring revenge for their former treachery, captured Torzhok and blocked its supplies of grain to Novgorod.
Several months later, he was defeated by his father-in-law on the Lipitsa River and had to retreat to Pereslavl; a helmet that he lost during the battle would be retrieved by archaeologists in 1808.
In 1222, Yaroslav, finally enthroned in Novgorod, overran all of Estonia and besieged its capital Kolyvan.
In 1236, he followed Daniel of Galicia's advice and moved from Novgorod to Kiev,[citation needed] leaving his son Alexander as his representative in the north.
In 1238, when the Mongols first invaded Kievan Rus' and his elder brother Yuri was killed in battle, Yaroslav left Kiev for Vladimir, where he was crowned grand prince.
[2] There he was poisoned by the Great Khan's mother Töregene and died a week after he had been allowed to return home.