Sieur de Beaulieu was a nobleman who entered the fur trade in the early French period, and was one of the voyageurs who accompanied Antoine Lamothe-Cadillac to establish the first permanent settlement at Le Detroit on July 24, 1701.
Plaques and statues in downtown Detroit celebrate the event, and the French-Canadian Heritage Society of Michigan has photographs of those statues on their website.
On their site the Society also lists the names of the French noblemen and informs us that the convoy also included fifty French soldiers and some passengers: "Chacornac, baron de Jaonnes; Pierre Dugue, sieur de Boisbriant; Antoine Lamothe, fils [brother]; Alphonse Tonty, baron de Paludy; a Recollet priest, and Francois Vaillant de Gueslis, S.J."
Images of these statues, and names of the gentlemen/voyageurs, are online at http://fchsm.habitant.org/plaque.html
However, Sieur de Beaulieu's actual name is Louis Chauvin, sieur de Beaulieu, and descendents of this man have told me that in the years I am searching for Beaulieu men, his descendents still used the Chauvin name.
There is a little more information on this site you might be interested in, if you can access it.
When I tried today, the pages were not available.
But the family trees of the persons who were in Detroit have been compiled into a document by Yves Drolet, a member of the societe genealoque canadienne-francais, and is supposedly available online at www.fchsm.habitant.org
It is called "Genealogical Tables of the Quebec Noblesse from the 17th to the 19th Century," and comes in both French and English.
When I searched the U.S. French Catholic Church Records in the Drouin Collection on Ancestry.ca many years ago, I discovered that in 1752 Sieur de Beaulieu had an infant baptized; and that in 1753 the priest "baptized Catherine fille legitime of Sr. Beaulieu and de spouse francoise..."
He appeared to be at Sault Ste Marie, and also seemed to be listed as a 'Commander pour le Roi."
Later I found a translation of above document headed: Makinac, Ste-Anne; Copie "Wisconsin Historical."
It read: "July 15, 1753, I administered holy Baptism to Catherine, legitimate daughter of Sieur Beaulieu and of his wife, Francoise, residing at Sault Ste Marie, born on April 18 last. The godfather was Mr. de Beaujeau, Captain Commanding for the King at this post; and the godmother Mlle Bourassa."
Sooner or later I will have to follow up on this man, to see if his boy children could have entered the fur trade using the name Beaulieu.
You have to follow every lead.