After 1630, Scottish migration to Ireland waned for a decade. In the 1630s, Presbyterians in Scotland staged a rebellion against Charles I for trying to impose Anglicanism. The same was attempted in Ireland, where most Scots colonists were Presbyterian. A large number of them returned to Scotland as a result. Charles I subsequently raised an army largely composed of Irish Catholics, and sent them to Ulster in preparation to invade Scotland. The English and Scottish parliaments then threatened to attack this army. In the midst of this, Gaelic Irish landowners in Ulster, led by Felim O'Neill and Rory O'More, planned a rebellion to take over the administration in Ireland.