Hugh O’Donnell and Hugh O’Neill felt their position and the power of Ulster was under threat from the English intruders. There were many series of battles defeating small English groups, the rebellion known as the Nine Years' War. The following year they wrote to King Philip II of Spain for help. The Spanish aid came in but landed in Kinsale in October 1601 miles away from Ulster. O’Neill and O’Donnell gathered their army and met in Kinsale on Christmas Eve 1601. They were defeated by a strong English army of 20,000 men, led by Lord Deputy Mountjoy. The Spaniards surrendered. Within two years, O’Neill and other leaders surrendered at the Treaty of Mellifont. At Mellifont, the Ulster chieftains agreed to accept English rule in their lands (sheriffs and judges). They also agreed to abandon Brehon Law, the Irish language and any further thoughts of rebellion. With less support from their people and more English control over Ulster, O’Neill and almost one hundred leading members of Ulster’s Irish families fled Ireland in an event known as the Flight of the Earls. They went to Spain, Italy and Rome. 