The Treaty of Mellifont (Irish: Conradh na Mainistreach Móire), also known as the Articles of Mellifont was signed in 1603 ending the Nine Years' War which took place in the Kingdom of Ireland from 1594 to 1603.
Following the English victory in the Battle of Kinsale, the leaders fighting in Cork returned to protect their homelands. The Lord Deputy of Ireland, Charles Blount, 8th Baron Mountjoy, had succeeded where his predecessor, Robert Devereux, 2nd Earl of Essex, had failed. However, Mountjoy knew that as long as Hugh O'Neill was still in hiding he was still a threat. Although most of the lesser chiefs allied with him had been compelled to submit, Rory O'Donnell, Brian Oge O'Rourke, Cuchonnacht Maguire (brother of Hugh Maguire), and Donal Cam O'Sullivan Beare remained loyal to The Great Earl. During the Spring of 1603, Lord Mountjoy concentrated his campaign in the northern counties and the province of Leinster. He ordered all land be scorched. Harvests and stock were destroyed and famine soon prevailed. Mountjoy and the English Privy Council had long urged Queen Elizabeth I of England to make peace. The war was costing three quarters of the Exchequer's annual revenue and the aged Queen had been obliged to maintain an army of 20,000 men for several years past. By contrast, the English army assisting the Dutch during the Eighty Years' War was never more than 12,000 strong at any one time. Horrified by the cost of the war, Elizabeth now dropped her insistence on unconditional surrender and authorised Mountjoy to treat with The O'Neill upon honourable terms.