Though his brother had extracted promises of loyalty from his Kievan subjects, Igor and his family, the Olgovichi, were unpopular and there was resistance against his accession.

He had reigned less than two weeks before the Kievans invited his cousin and rival, Iziaslav II, to be their prince.

Reneging on a promise he had made not to seek power, Iziaslav attacked and defeated Igor and his brother Sviatoslav.

Sviatoslav escaped, but Igor got bogged down in some marshes and was unable to flee because of an infirmity in his legs.

Igor is venerated as a saint in the Eastern Orthodox Church, with his feast day being on 19 September.