 In 1642 the English Civil War broke out , dividing the country into the Royalist supporters of Charles , and the Parliamentarians . In the aftermath of the battle of Edgehill in October , Parliament became concerned that Charles might advance on London . John Venn took control of Windsor Castle with twelve companies of foot soldiers to protect the route along the Thames river , becoming the governor of the castle for the duration of the war . The contents of St George 's Chapel were both valuable and , to many Parliamentary forces , inappropriately high church in style . Looting began immediately : Edward IV 's bejewelled coat of mail was stolen ; the chapel 's organs , windows and books destroyed ; the Lady Chapel was emptied of valuables , including the component parts of Henry VIII 's unfinished tomb . By the end of the war , some <unk> oz ( 101 kg ) of gold and silver plate had been looted . 
