Above : Castle Of Bunratty, Storage Of Arms & Ammunitions

Now, when the peace had been concluded, it was thought that some military enterprise should be attempted againsl the Parliamentarians, and especially against Munroe, who had madfl preparations to march southward and invade Leinster. He hoped to effect a junction at Glasslough (Co. Monaghan) with his brother George’s forces, and subsequently with those of Sir Robert Stewart. This junction O’Neill resolved to prevent. He marched his troops from Cavan, pitched his tents at Benburb on the Blackwater, and there awaited the enemy. Munroe hurried south from Armagh, and early in the morning of June 5th (1646), the two armies were face to face on the same side of the river. O’Neill had selected his position with care.

His centre was posted on and about the little bushy hill of Knocknacloy ; his right wing was protected by a bog ; his left by the river Oona, which just there joins the Blackwater. His forces amounted to some 5,500 men, and probably exceeded by a little those of Munroe ; they were also of better quality. But he had no artillery, with which the English and Scotch troops of his opponents were well provided.
O’Neill disposed his infantry in two lines with a free space between them.

They were armed partly with muskets and partly with very long pikes. The cavalry were posted on the wings. Munroe also arranged his infantry in two lines : the Oona being on his right and the Blackwater at his rear, but his left wing was unsheltered.

An attack made on the Irish front by Lord Ards was repulsed by the cavalry led by Henry Ruadh, O’Neill’s son. Lord Blaney’s artillery succeeded no better, and Eoghan’s captains pressed him to order his main body to charge. But he restrained their impatience, and began slowly to mass his best troops on his right wing, and to press on the unprotected British left. To oppose him, Munroe was obliged to order a change of front, and in executing this manoeuvre his ranks fell into confusion. Still refusing to give the much-desired word, O’Neill continued to force the enemy back into the angle formed by the Oona and the Blackwater. The evening was closing in, when at last the General raised his hat and bade the officers around him pass the word to charge.

A ringing cheer answered him, and the Irish bore down on their foes. The British resisted bravely, but it was not for long. Soon they turned in flight, and the greatest Irish victory since that of t)eat An -&tA tluvoe (Yellow Ford) was won. All the British standards, tents and baggage fell into O’Neill’s hands, as well as many prisoners, whom he treated with all courtesy. Over 2,000 of Munroe’s men lay dead on the field ; Eoghan Ruadh had lost scarcely 200 slain and wounded.
In the south, too, success crowned the arms of the Confederates.

In July a force under Lord Muskejrry captured the important Castle of Bunratty near Limerick, and in it good stores of arms and ammunition.
Had this tide of victory been taken in the flood, and the campaign been vigorously prosecuted, great results might have been hoped for, but alas ! this was not done. Dissensions and jealousies were as rife as ever in the Supreme Council. O’Neill was ordered to march his army southward, and, obeying, lost most of the fruits of Benburb.