The idea of revolt against Andros arose as early as January 1689, before news of the December 1688 Glorious Revolution reached Boston. After William III and Mary II took the throne, Increase Mather and Sir William Phips, Massachusetts agents in London, petitioned them and the Lords of Trade for restoration of the Massachusetts charter. Mather furthermore convinced the Lords of Trade to delay notifying Andros of the revolution. He had already dispatched to Bradstreet a letter containing news that a report (prepared before the revolution) stating that the charter had been illegally annulled, and that the magistrates should "prepare the minds of the people for a change." News of the revolution apparently reached some individuals as early as late March, and Bradstreet is one of several possible organizers of the mob that formed in Boston on April 18, 1689. He, along with other pre-Dominion magistrates and some members of Andros' council, addressed an open letter to Andros on that day calling for his surrender in order to quiet the mob. Andros, who had fled to the safety of Castle Island, surrendered, and was eventually returned to England after several months in confinement.