[3] He was wounded at the Battle of Long Island on 22 August 1776, while leading the 1st Grenadier Battalion in the army of Sir William Howe with the rank of lieutenant colonel.

[1][4] At time of the Battle of Trenton on 26 December 1776, he served as acting commander of Major General James Robertson's 1st British Brigade at New York City.

[10] Near sunset, the advancing 2nd Grenadiers walked into a trap set by George Weedon's fresh Virginia brigade, which was deployed on a reverse slope with its right flank thrown forward so as to take the British line in enfilade.

Once he found his troops in a tight spot, Monckton asked Hessian Captain Johann von Ewald to ride back and summon reinforcements.

[17] In March 1778, Secretary of State for the American Colonies George Germain, 1st Viscount Sackville, sent orders permitting the evacuation of Philadelphia.

Worried about being trapped in the Delaware River by a French fleet, the new British commander Henry Clinton determined to move most of his army to New York by land.

[18] The naval transports were packed with most of the army's women and children, 3,000 loyalist civilians, sick soldiers, and the unreliable Ansbach-Bayreuth mercenaries.

When Lee arrived near the British positions, Clinton turned back to assist his covering party with strong rear guard forces, including the two grenadier battalions.

Farther to the left, Anthony Wayne directed soldiers led by Walter Stewart and Nathaniel Ramsey into some woods.

Though their commander Colonel Henry Trelawney and 40 men were hit, the Brigade of Guards and two companies of the 1st Grenadier Battalion rushed the woods.

Case shot from Oswald's guns ripped into the grenadiers from a range of 40 yards (37 m), but they stormed the hedgerow anyway, driving back Olney's men.

The action was so chaotic that a party of 16 grenadiers found themselves amid Olney's brigade, but the Americans were so focused on getting away that they paid no attention to their enemies.

However, Hessian Adjutant General Carl Leopold Baurmeister wrote, "Colonel Monckton was killed, a great loss indeed.

The inscription on his grave marker reads: "Lt. Col. Henry Monckton who on the plains of Monmouth 28 June 1778 sealed with his life his duty and devotion to his king and country.

This memorial erected by Samuel Fryer whose father a subject of Great Britain sleeps in an unknown grave.

[26] In one account, Monckton's mortal wounding and the loss of the colors came late in the day at the hands of Anthony Wayne's troops in front of Washington's main position.