The comté de Saint-Hyacinthe was created in 1830 though people began to settle the area between 1756 and 1779. It was part of the district of Montreal and was wedged between the comtés de Richelieu and of Rouville in the north, Shefford in the south and the districts of Trois-Rivières and Sherbrooke in the east. Situated in the Richelieu valley, the comté is bathed in the south by the Richelieu and is crossed by the Noire and Yamaska rivers where navigation was difficulty because of the number of rapids that limited settlement until the 1780s.  The landscape is very flat and is broken only by the Saint-Hilaire, Rougemont and Yamaska hills. The soil is extremely rich and varied  and is well suited to the cultivation of cereals and livestock breeding. 
The comté was made up of seven seigneuries: Ramesay, Rosalie, Delorme, Debartzch, Mondelet, Yamaska and Dessaulles. In 1831, the village of Saint-Hyacinthe had a population of around a thousand people. It contained an important seminary where the sons of some Patriote leaders, including Papineau, studied and was also the site of the tribunaux de comté that had a degree of judicial autonomy.  The presence of a significant number of inns, including two in Saint-Hyacinthe was closely related to the importance of the road network connecting Vermont with Trois-Rivières and Québec. Cereal production was the main economic activity for most habitants in the region but there was some diversification of the rural economy with tanneries, distilleries and saw-mills. Greer argues that the region had been prosperous since the mid-1790s.  The population of the comté increased in the 1830s and by 1832 had reached 14,000 people living in six parishes: La Présentation, Saint-Damase, Saint-Césaire, Saint-Pie, Sainte-Rosalie and Saint-Dominique. There was a large French majority in the comté who elected francophone reformist deputies.
In 1792 when Lower Canada was divided into 27 electoral comtés, the seigneurie de Saint-Hyacinthe was attached to the comté de Richelieu. The first two deputies elected lived in Saint-Denis: the land surveyor Séraphin Cherrier and the merchant Pierre Guérout. In 1829, when the number of comtés was increased to 40, the old comté de Richelieu was divided into four including Saint-Hyacinthe. Louis-Antoine Dessaulles, deputy of Richelieu since 1816, represented the new comté with Louis Raynaud dit Blanchard. Although newly created, the comté was a Patriote stronghold in the years leading up to the Rebellions. The seigneur Dessaulles was married to a sister of Louis-Joseph Papineau who enjoyed great popularity in the area. In 1832, following a request for Aylmer, Dessaulles agreed to sit on the Executive Council where he put forward Patriote ideas. Louis Raynaud dit Blanchard (1830-1838), Louis Poulin (1832-1834) and Thomas Bouthillier (1834-1838) were elected for the comté in his place and all three were involved in the rebellion. Bernard identified 86 habitants in the area as Patriotes of whom the main agitators were Thompson, Dr Thomas Bouthillier, Eusèbe Cartier, Blanchard, Poulin, Bouthillier, Dr Boucher de La Bruère, Jean-François Têtu, F.X. Langelier and A.-A. Papineau.  They came largely from the villages and Choquette suggests that the rural population played little part in the risings.
While there were loyalists in the region, they tended to seek support from the surrounding comtés. However, they held assemblies at Abbotsford on 13 November 1837 and others were held in Granby and Rouville where loyalists were more important. The comté de Saint-Hyacinthe saw at least five Patriote assemblies from 1834 held in the town of Saint-Hyacinthe. These intensified in 1837 after the rejection of the Ninety-Two Resolutions and the most popular held on 1 June 1837 was attended by 1,600 people. In addition some habitants took part in assemblies in other areas especially at Saint-Ours and Saint-Charles. There were several Patriote charivaris in the region during the late summer and autumn of 1837 including one directed against Sir John Colborne in the village of Saint-Hyacinthe.  The comté de Saint-Hyacinthe was not a theatre of military operation between loyalists and rebels but it was of major importance in the Patriote network for provisioning their forces especially when Saint-Charles was an armed camp. No habitant from the comté was arrested or imprisoned and the role of the habitants was limited to providing means of escape to fugitives including Louis-Joseph Papineau and Wolfred Nelson. Senior maintained that Bouthillier and A.-A. Papineau led forty men from Saint-Hyacinthe to Saint-Denis and that at the time of the battle of Saint-Charles they were at the head of two regiments of rebels from the comté. After the battle of Saint-Charles, Papineau took refuge with his sister in Saint-Hyacinthe but was able to escape when Gore and 300 regular British troops arrived at the village. After their campaign in the Richelieu, the soldiers remained four or five days in the village and Choquette says that there were few reprisals and little destruction in the area. Calm quickly returned to the comté largely because of the substantial police presence under P-E Leclerc. The only significant event in the comté in 1838 was the arrest of De La Bruyère.
 Voyer, Louise, Saint-Hyacinthe, de la seigneurie à la ville québécoise, (Libre expression), 1980, p. 13
 Ibid, Bouchette, Joseph, Description topographique du Canada 1815, p. 323; Hudon, Christine, Prêtres et fidèles dans le diocèse de Saint-Hyacinthe 1820-1875, (Septentrion), 1996, pp. 21-21.
 Parizeau, Gérard, Les Dessaulles, seigneurs de Saint-Hyacinthe, (Fides), 1976, p. 52 and Blanchard, Raoul, L’ouest du Canada français, (Beauchemin), 1953, Vol. 1, pp. 30-31.
 Choquette, C.P., Histoire du Séminaire de Saint-Hyacinthe depuis sa fondation jusqu'à nos jours, (Imprimerie des sourds-muets), 1911.
 Ibid, Greer, Allan, The patriots and the people, p. 92.
 Ibid, Greer, Allan, The patriots and the people, p. 46.
 Ibid, Laporte, Gilles, Patriotes et Loyaux, pp. 194-206.
 DPQ, p. 162.
 DPQ, p. 346.
 DPQ, pp. 225-226.
 DPQ, p. 636.
 Ibid, Parizeau, Gérard, Les Dessaulles, seigneurs de Saint-Hyacinthe, p. 55.
 Messier, p. 58.
 DPQ, p. 614.
 DPQ, p. 102; Messier, p. 78.
 Messier, pp. 95-96.
 Messier, p. 455.
 Messier, p. 270.
 Messier, pp. 368-369.
 Choquette, C.P. Histoire de la ville de Saint-Hyacinthe, Saint-Hyacinthe, 1930, p. 145.
 Ibid, Bernard, Jean-Paul, Assemblées publiques, résolutions et déclarations de 1837-1838, pp. 291-293.
 Ibid, Bernard, Jean-Paul, Assemblées publiques, résolutions et déclarations de 1837-1838, pp. 57-61.
 See below, pp. 260-261.
 Ibid, Choquette, C.P. Histoire de la ville de Saint-Hyacinthe.
 Ibid, Senior, Elinor Kyte, Redcoats & Patriotes: The Rebellions in Lower Canada 1837-38, p. 82.
 Ibid, Choquette, C.P. Histoire de la ville de Saint-Hyacinthe, p. 145. The deposition of Alexis-Arthur Delphos stated that on 23 November 1837, 60 armed men under the command of Thomas Bouthillier de Saint-Hyacinthe asked for absolution from curé Édouard Crevier before leaving for the fighting at Saint-Charles: Archives nationales du Québec, fonds P224, pièce no. 878.
 Ibid, Choquette, C.P. Histoire de la ville de Saint-Hyacinthe, p. 154