On 11 September 1630 Ranelagh was appointed joint President of Connaught alongside Charles Wilmot, 1st Viscount Wilmot of Ahlone, who had occupied this post alone since 3 June 1616. Ranelagh went to Athlone and took over the command of the troops and fortresses of the province, whereas Wilmot tried to play an important role in Dublin, but kept the title and outlived Ranelagh, dying shortly after Ranelagh, late in 1643 or early in 1644. After the outbreak of the Irish Rebellion in 1641 Ranelagh defended Athlone during 1642 against confederate troops led by James Dillon. in January 1643 the Lord Justices (Sir Henry Tichborne and John Borlase) sent Sir Richard Grenville to Athlone to bring him provisions, but Ranelagh decided to abandon Athlone and he and the garrison accompanied Grenville back to Dublin. On the way back they met a confederate force that Grenville defeated in the Battle of Rathconnell on 7 February 1643. At Dublin Ranelagh was accused to have failed in his duties as president of Connaught. A document of 74 articles was written and sent to the King. Ranelagh was first forbidden to leave Ireland, but the King then allowed him to come to Oxford and explain himself.