Hearing of the rebellion, Charles rushed back to London to co-ordinate a fight-back. However, he had reckoned without the intransigence of Pym and other opposition MPs who were reluctant to give Charles command of an army. Charles looked to Parliament for supply and soldiers in a time of crisis; what he received was the Grand Remonstrance, a document outlining his alleged religious and political abuses over the preceding decade. The Grand Remonstrance represented a direct attack on royal authority and Charles responded by launching an attack on Parliament. Accompanied by 400 guards, Charles set off for Westminster on 4th January 1642, determined to arrest Pym and his supporters. However, Pym had learned of the King's plans and had already gone into hiding. When Charles arrived, he found that 'the birds had flown' and Speaker Lenthall was unwilling to assist with his enquiries. Buffeted by pro-Parliament mobs as he returned to Whitehall, Charles and his family set off for the relative safety of Hampton Court. In his absence, Parliament sanctioned the execution of several Catholic priests and began to seize control of strategic sites, including the arsenal at Tower Hill. Charles' decision to leave London reinforced the rift between Crown and Commons and initiated the process of forcing people to choose sides.