Tyrone's 9 year war with England

Hugh O'Neill, Earl of Tyrone

Queen Elizabeth I  feared the loss of Ireland under Tyrone's succeeding rebellion and his association with Spain ( the pending arrival of an army of Invasion).  Under Earl of Essex, she dispatched 16,000 troops to Dublin. This was the largest ever assembled under her reign and at a great cost to the Crown. After a year the English army was reduced by death in combat and disease as well as dissertion to some 3000 troops.