Lieutenant-Colonel George L'Estrange was the military commander in Manchester in 1819. On 14th August he received a request from William Hulton to provide military assistance to prevent trouble at the meeting at St. Peter's Field on 16th August.. L'Estrange decided to employ 600 members of the 15th Hussars, and several hundred infantrymen in the 31st and 88th Foot. He also had a detachment of the Royal Horse Artillery, 400 members of the Cheshire Yeomanry and 120 members of the Manchester and Salford Yeomanry Cavalry.
Lieutenant-Colonel L'Estrange's plan was to surround the St. Peter's Field with troops. The cavalry were in the front and were to be used to disperse the crowd if the magistrates decided on that action. The infantrymen were to be called in if the meeting turned into a riot. L'Estrange decided that the Royal Horse Artillery would only be used in a emergency.
At about 12.30 William Hulton came to the conclusion that "the town was in great danger". Hulton therefore decided to instruct Joseph Nadin, Deputy Constable of Manchester, to arrest Henry Hunt, Joseph Johnson, John Saxton and James Moorhouse, who were on the hustings at the time. Nadin replied that this could not be done without the help of the military. Hulton then wrote two letters and sent them to Lieutenant Colonel L'Estrange, the commander of the military forces in Manchester and Major Trafford, the commander of the Manchester & Salford Yeomanry.
Major Thomas Trafford, who was positioned only a few yards away at Pickford's Yard, was the first to receive the order to arrest the men. Major Trafford chose Captain Hugh Birley, his second-in-command, to carry out the order. Local eyewitnesses claimed that most of the sixty men who Birley led into St. Peter's Field were drunk. Birley later insisted that the troop's erratic behaviour was caused by the horses being afraid of the crowd.
When L'Estrange arrived at St. Peter's Field he asked William Hulton what was happening. Hulton replied: "Good God, Sir, don't you see they are attacking the Yeomanry? Disperse them." L'Estrange ordered Lieutenant Jolliffe and the 15th Hussars to rescue the Manchester & Salford Yeomanry. In the next few minutes eleven people were killed and about 400, including 100 women, were wounded.
That night Lieutenant-Colonel George L'Estrange wrote a report on the day's proceedings and sent it to Major General Sir John Byng, Commander of the Northern District.
The Magistrates, the Boroughreeves and Constables of Manchester and Salford, an immense body of Special Constables, and the various force of military and artillery were in motion for their appointed duties. The latter consisted of our own Yeomanry Cavalry, under Major Trafford; the Prince Regent's Cheshire Yeomanry were under Lieutenant-Colonel Townsend; the 15th Hussars from the Barracks, under Lieutenant-Colonel Dalrymple; a detachment of the 88th Foot, now stationed in the King Street Barracks, under Colonel McGregor; the Royal Horse Artillery, under Major Dyneley; and a detachment of the 31st Foot, under Lieutenant-Colonel L'Estrange, the able, intelligent, and active officer who commanded the whole and made all the necessary arrangements for the occasion.
The magistrates assembled here in consequence of the disturbed state of the district, directed me to have the troops in readiness to assist the civil power in case of necessity, at the time of the meeting proposed for this day. The magistrates were in attendance near St. Peter's Church: and Mr. Trafford, a Justice of the Peace for the counties of Chester and Lancaster, was appointed to remain with the cavalry.
Early in the afternoon, the civil power finding it necessary that the troops should act in aid of them, it was deemed expedient that the cavalry should advance; and a warrant was executed, preceded by the civil authority under which two persons Hunt and Johnson, named therein were arrested; as were also two persons named Saxton and Sykes who were active, as I am told on the hustings. This service was performed with the assistance of the cavalry.
The infantry was in readiness, but I was determined not to bring them into contact with the people, unless compelled to do so by urgent necessity; not a shot therefore has been fired by the populace against the troops. I have, however, great regret in stating that some of the unfortunate people who attended this meeting have suffered from sabre wounds, and many from the pressure of the crowd. One of the Manchester Yeomanry, if not dead, lies without hope of recovery; it is understood he was struck with a stone. One of the special constables has been killed.
The Manchester Yeomanry, under Major Trafford, and the Cheshire Yeomanry under Lieutenant-Colonel Townsend, who had come on a very short notice from the county magistrates (many of them from a great distance) were most active and efficient in discharge of their duty. The committee, now sitting, consider it necessary to keep all the troops ready, though every means will be adopted to prevent the necessity of their acting.
Carriages were brought to convey the wounded to the Manchester Infirmary. For some time the town was patrolled by the troops, the streets being nearly empty, and the shops for the most part closed. We then returned to the barracks.