On the island of Montreal was the most important of the seigneuries in the district bearing its name.  It was held by the Seminary of St Sulpice, and its six parishes contained in 1712 a population of over two thousand.  The soil of the island was fertile and the situation was excellent for trading purposes, for it commanded the routes usually taken by the fur flotillas both from the Great Lakes and from the regions of Georgian Bay.  The lands were steadily rising in value, and this seigneury soon became one of the most prosperous areas of the colony.  The seminary also owned the seigneury of St Sulpice on the north shore of the river, some little distance below the island.

Stretching farther along this northern shore were various large seigneuries given chiefly to officers or former officers of the civil government, and now held by their heirs.  La Valterie, Lanoraie, and Berthier-en-Haut, were the most conspicuous among these riparian fiefs.  Across the stream lay Chateauguay and Longueuil, the patrimony of the Le Moynes; likewise the seigneuries of Varennes, Vercheres, Contrecoeur, St Ours, and Sorel.  All of these were among the so-termed military seigneuries, having been originally given to retired officers of the Carignan regiment.  A dozen other seigneurial properties, bearing names of less conspicuous interest, scattered themselves along both sides of the great waterway.  Along the Richelieu from its junction with the St Lawrence to the outer limits of safe settlement in the direction of Lake Champlain, a number of seigneurial grants had been effected.  The historic fief of Sorel commanded the confluence of the rivers; behind it lay Chambly and the other properties of the adventurous Hertels.  These were settled chiefly by the disbanded Carignan soldiers, and it was their task to guard the southern gateway.

The coming of this regiment, its work in the colony, and its ultimate settlement, is an interesting story, illustrating as it does the deep personal interest which the Grand Monarque displayed in the development of his new dominions.  For a long time prior to 1665 the land had been scourged at frequent intervals by Iroquois raids.  Bands of marauding redskins would creep stealthily upon some outlying seigneury, butcher its people, burn everything in sight, and then decamp swiftly to their forest lairs.  The colonial authorities, helpless to guard their entire frontiers and unable to foretell where the next blow would fall, endured the terrors of this situation for many years.  In utter desperation they at length called on the king for a regiment of trained troops as the nucleus of a punitive expedition.  The Iroquois would be tracked to their own villages and there given a memorable lesson in letters of blood and iron.  The king, as usual, complied, and on a bright June day in 1665 a glittering cavalcade disembarked at Quebec.  The Marquis de Tracy with two hundred gaily caparisoned officers and men of the regiment of Carignan-Salieres formed this first detachment; the other companies followed a little later.  Quebec was like a city relieved from a long siege.  Its people were in a frenzy of joy.