The downfall of Lord Essex did no damage to Lord Mountjoy's career. After the failure of
his rebellion, Essex shocked many by denouncing his sister Penelope, who was Mountjoy's mistress, as a traitor, which inevitably raised the question of his own possible involvement; but the Crown, anxious to retain Mountjoy's services, and also to show as much leniency as possible to the defeated rebels, simply ignored the accusation. On 24 February 1600, Mountjoy landed in Ireland as
Lord Deputy following Lord Essex and in the ensuing years brought the
Nine Years' War to an end. The leader of the rebellion,
Hugh O'Neill, Earl of Tyrone, wrote about Mountjoy's "refined manners" that he would lose a whole season of campaigning "while waiting until breakfast is prepared to his mind!". Despite this, Mountjoy proved that he was quite qualified to pursue the war. In early 1600, Mountjoy had dispatched
Sir Henry Docwra with an army of 4,200 troops to land at Culmore to erect a fortress commanding the shores of Lough Foyle in the north-west of Ulster. To prevent Hugh O'Neill from sending a strong force to repulse Dowcra's forces, Mountjoy advanced in force from Dublin to Newry causing O'Neill to fear a southern advance into Tyrone.Mountjoy advanced to the location he found the previous summer at the River Blackwater, which commanded safe and secure passage into Tyrone, previously inaccessible, and set about erecting a new fort. O'Neill having observed this
burnt his capital at Dungannon and fled to his last refuge in
Glenconkeyne. He showed similar moderation in putting down the abortive risings in
Cork,
Waterford and
Wexford, where the
aldermen, apparently with some vague idea of gaining greater toleration for
Roman Catholics, refused to proclaim the new King: in Cork, three insurgents were hanged after a summary trial, but the rest were acquitted or pardoned. As part of the
Plantation of Ulster, the majority of the barony of
Loughinsholin was detached from
County Tyrone and made part of the newly created
County Londonderry. The rest of Loughinsholin along with the northern parts of
Dungannon barony were merged to create the short-lived barony of Mountjoy. It would later be amalgamated with the barony of Dungannon. ==Later life==