When the return of Bonaparte to France re-kindled the war in Europe, Lieut.-General Lord Hill was selected to hold an important command in the army in Flanders under Field-Marshal the Duke of Wellington; and he was placed at the head of a corps of the allied army at the memorable battle of Waterloo, on the 18th of June, 1815, when the power of Bonaparte was annihilated by British skill and valour, and peace was acquired for Europe. The honorary distinctions conferred upon Lord Hill for his important services, were,—Knight Grand Cross of the Order of the Bath,—Knight Grand Cross of the Royal Hanoverian Guelphic Order,—a medal for the battle of Waterloo,—a cross and three clasps for the battles of Roleia, Vimiera, Corunna, Talavera, Vittoria, Pyrenees, Nivelle, Nive, and Orthes; the Turkish Order of the Crescent,—Grand Cross of the Tower and Sword of Portugal, Commander of Maria Theresa of Austria,—St. George of Russia, and Wilhelm of Holland. He was presented with the freedom of the city of London; and was appointed governor of Hull, and Colonel of the ninety-fourth regiment. In 1817 he was removed to the FIFTY-THIRD regiment.
In 1825 Lord Hill was promoted to the rank of general; and on the 15th of February, 1828, he was appointed General Commanding in Chief, the important duties of which appointment he performed with reputation and advantage to the service fourteen years. He was appointed Colonel of the Royal Regiment of Horse Guards, and Governor of Plymouth, in 1830. His Lordship's resignation of the command of the Army, in August, 1842, was announced in the following General Order:
"Horse Guards, 15th August, 1842.
"General Lord Hill finds it necessary to resign the Command of the Army on account of his Lordship's present state of health, and Her Majesty has been graciously pleased to accept his Lordship's resignation.
"When Lord Hill assumed the command which he now resigns, he expressed, in General Orders, his confident hope, that from the General and other Officers, as well as from the Public Departments of the Army, he should receive that support which should enable him to fulfil the important trust reposed in him.
"That hope has not been disappointed, but, on the contrary, realized beyond Lord Hill's most sanguine expectation.
"The conduct of the Troops has, both in the Field and in Quarters, furnished, during Lord Hill's command of them, an example of discipline, regularity, and general efficiency, not to be surpassed, and the Officers have, by their devotion to their duty, enabled his Lordship to maintain the Army in that creditable state. The Officers have, therefore, established their claim to Lord Hill's lasting gratitude and esteem.
"His Lordship cannot, then, but with painful feelings take leave of Officers, Non-Commissioned Officers, and Soldiers, whose conduct has been so uniformly approved by their Sovereign and by their Country.
"These feelings are, however, greatly alleviated and consoled by the reflection that the Command of the Army is now to be resumed by the Duke of Wellington, the ever vigilant and most influential Guardian of its Interests, and whose achievements have raised its character to the highest Pinnacle of Glory."
On the 3rd of September, 1842, Lord Hill was advanced to the dignity of Viscount, by Her Majesty, in consideration of his eminent military services, and in approbation of the ability with which His Lordship had discharged, for a lengthened period, the important duties of General Commanding-in-Chief.