Before Charles returned from Scotland, which he had visited in the vain expectation of bringing back with him an army which might give him the control over the English Parliament, an event occurred which brought to light the disastrous impolicy of his opponents in leaving upon the throne the man who was most hostile to their ideas. The Irish Roman Catholic gentry and nobility, having been driven into Royalism by fear of Puritan domination, had agreed with Charles to seize Dublin and to use it as a basis from which to send him military aid in his struggle against the Parliament of England. In October 1641, before they could make up their minds to act, an agrarian outbreak occurred in Ulster, where the native population rose against the English and Scottish colonists who had usurped their lands. The rising took the form of outrage and massacre, calculated to arouse a spirit of vengeance in England, even if report had not outrun the truth--much more when the horrible tale was grossly exaggerated in its passage across the sea. Before long both classes of Roman Catholic Irishmen, the Celtic peasants of the North and the Anglo-Irish gentry of the South, were united in armed resistance to the English Government. It was a foregone conclusion that an attempt to reconquer Ireland would be made from England. Incidentally the purpose of doing this brought to a point the struggle for the mastery at Westminster. If an army were despatched to Ireland it would, as soon as its immediate task had been accomplished, be available to strike a decisive blow on one side or the other. It therefore became all-important for each side to secure the appointment of officers who might be relied on--in one case to strike for the Crown, in the other case to strike for the Commons. Pym, who was leading his party in the House with consummate dexterity, seized the opportunity of asking, not merely that military appointments should be subject to Parliamentary control, but that the King should be asked to take only such councillors as Parliament could approve of. Cromwell was even more decided than Pym. The King having named five new bishops, in defiance of the majority of the Commons, it was Cromwell who moved for a conference with the Lords on the subject, and who, a few days later, asked for another conference, in which the Lords should be asked to join in a vote giving to the Earl of Essex power to command the trained bands south of the Trent for the defence of the kingdom, a power which was not to determine at the King's pleasure, but to continue till Parliament should take further order.