Two atrocities committed by the British during the Napoleonic period, among others that definitely stand alone are the terror bombardment of Copenhagen in 1807 where the civilian population was definitely targeted and the forced evacuation of the Portuguese civilian population to Lisbon and Torres Vedras.

Copenhagen:

The following quotation from a British engineer officer who made two interesting remarks about the British attack on Copenhagen in 1807. He states that he considered the British siege and attack on Copenhagen an 'incendiary bombardment' and that it was a 'barbarous measure.'

'I should have suggested several improvements that appeared to me from my own experience and reflection to be essential...I considered the British Army...to be incapable of succeeding in a siege...without either having recourse to the barbarous measure of incendiary bombardment, or without an enormous sacrifice of the lives...in sanguinary assaults...which might be rendered unnecessary by a more efficient organization of the Royal Engineer department, and especially by forming a well-instructed and well-disciplined body of engineer soldiers...The better instruction of the junior officers of the Royal Engineers appeared no less essential, for at that time they were not even taught the theory of the attack of fortresses...and the examination for commissions were merely a matter of form, and no genuine test for proficiency. As for practical instruction, they had none, for they were sent on service without ever having seen a fascine or gabion, without the smallest knowledge of the military passage of rivers, of military mining, or any other operation of a siege, excepting what they may pick up from French writers, of which a striking proof occurred in Sir John Moore's retreat, when all attempts to blow up stone bridges...made by officers of the Corps, myself amongst others, failed...with the exception of only one, which Lieutenant Davy, a very promising young officer, succeeded in completely destroying, but at the expense of his own life, which he lost from not understanding the very simple precautions necessary to insure the safety of the person who fires the train of the mine. For my part, I should not have even known how to make a battery in the attack on Copenhagen, the first siege in which I was employed, but from the information I derived from a French book on the subject.'-Charles William Pasley RE, 1811.

'When the British artillery fell silent at noon on 5 September, the inhabitants of Copenhagen were stunned and terrified, and the city bore witness, as Cathcart and Gambier had warned in the proclamation they issued when British troops landed on Zealand, to 'the horrors of a besieged and bombarded capital'. One-fifth of Copenhagen's population-20,000 people-had fled their homes to
Christianshavan or Amager and two thousand of them (2 percent of the total population) had been killed. Many of the British bombs and shells had penetrated right to the cellars of houses, the natural place of refuge, and this had increased the numbers of fatalities. It took several more days to bring the fires under control, and the flames of the ruined Frue Kirke were not entirely extinguished until the end of September. About one-twelfth of central Copenhaged was burnt to the ground and buildings over a much larger area of the city had sustained lesser or greater degress of damage.'-Munch-Peterson, 200.

'If it is found by experience that the destruction of the fleet is actually not within the power of our mortar batteries, we must then of necessity resort to the harsh measure of forcing the town into our terms, by the sufferings of the inhabitants themselves. But to give this mode of attack its fullest effect, it is necessary to completely invest the place, and oblige by that means, all persons of whatever description, to undergo the same hardships and dangers.'-Lieutenant Colonel George Murray, deputy quartermaster-general of the Copenhagen expedition, cited by Munch-Peterson, 195.

See both Wellington’s Engineers by Mark Thompson and Defying Napoleon: How Britain Bombarded Copenhagen and Seized the Danish Fleet in 1807.

Torres Vedras:

‘It becomes very necessary that this state of things should have an end for the complete destruction of the peasantry by famine will be the consequence of its continuance as well as the ruin of the better orders.’-a British officer remarking on the forced evacuation of the Portuguese population to Lisbon.

‘It was a melancholy sight to see the poor natives, carrying their children, and any little thing which they were able to bring with them, moving along the road, after having left their homes and property-travelling they knew not whither, desolate and friendless. In a few days they might be reduced to beg, or perhaps die of hunger.’-an eyewitness.

‘…everything which prudence and humanity could suggest was done by the inhabitants of Lisbon to alleviate the public misfortune. Charitable institutions were set on foot and food was daily distributed to such of the fugitives as were necessitous and helpless.-Alexander Dickson.

‘misery and wretchedness of the refugees is beyond description, numbers are perishing from disease and want.’-an eyewitness.

Of the approximately 300,000 Portuguese civilians who were forcibly removed to Lisbon inside the Lines of Torres Vedras, about 40,000 died of hunger and disease. Some of them, under pain of execution, refused to go to Lisbon and instead ‘escaped’ to Peniche, where an average of 25-30 died per day; the peak was 65 in a single day.

The Portuguese government was unable to support these people that they and the British had forced from their homes. The food distribution ‘system’ was inadequate. Mules requisitioned to pull vehicles for food distribution were not used, both the owners and the animals were left ‘starving and shivering.’

See The Lines of Torres Vedras by John Grehan, 159-160.