The Massachusetts agents then petitioned the new monarchs and the Lords of Trade for restoration of the old Massachusetts charter. Mather furthermore convinced the Lords of Trade to delay notifying Andros of the revolution. He had already dispatched a letter to previous colonial governor Simon Bradstreet containing news that a report (prepared before the revolution) stated 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 and 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, Randolph, Dudley, and other dominion supporters were arrested and imprisoned in Boston.