According to the biography of Sarah Allen in the Généalogie du Québec et d'Amérique française, ongoing conflicts between New France and New England and their respective Indigenous allies were exacerbated by Europe's War of the Spanish Succession, which saw England declare war on France. The war spread to America. New France feared that New England would attack Acadia to gain control of the territory. To divert English forces from Acadia, the French made a number of incursions into New England with the help of their Indigenous allies. A common practice among the French was to set out in winter on snowshoes, accompanied by a number of Indigenous allies, to launch raids on New England villages. The French and their Indigenous allies would often bring people captured during the raids back to New France to be integrated into their communities, sold or ransomed. Given its proximity to New France, particularly Fort Chambly, and its isolation from other English settlements, Deerfield, Massachusetts, was a frequent target.

As James L. Swanson describes in his 2024 book The Deerfield Massacre: A Surprise Attack, a Forced March, and the Fight for Survival in Early America, as early as the fall of 1703, French forces and their Indigenous allies began gathering at Fort Chambly to plan an expedition to Deerfield under the command of Lieutenant Jean-Baptiste Hertel de Rouville.

In The Deerfield Massacre, Swanson describes the approach of the raiding force from New France. The main group of attackers bypassed the houses north of the village, including the Allen home, so as to maintain the element of surprise. Their target was the closely built houses inside the palisade, where the bulk of the population lived. "If they attacked the scattered houses outside the fort, they would alert the whole town that Deerfield was under siege," writes Swanson. "Total surprise was necessary for success. Any premature alarm, even one minute before the attack, would spoil the surprise and give the English just enough time to spring from their beds, dress in a hurry, and grab their muskets for a fight. So the raiders ignored what they saw, and passed over the houses that they encountered on the way to the fort."

In Our Captive Ancestors from the 1704 Deerfield Raid, French Canadian genealogist Kim Kujawski notes that as the French and Indigenous forces approached Deerfield, they noticed that snow drifts had practically reached the top of the palisade, allowing a few attackers to easily climb over and unlock the gate to let the rest in. In the ensuing attack, raiders killed or captured residents, stole valuable goods and set houses on fire. Despite resistance from Deerfield citizens, the French and their Indigenous allies captured 112 people, most of whom were women and children. Eleven-year-old Sarah Allen was one of them.

By early morning, a force of English militiamen arrived in Deerfield and, together with garrison soldiers and village residents, chased the remaining French and Indigenous raiders out of town. In a skirmish that would become known as the "Meadows Fight," two Deerfield residents, two soldiers and five militiamen were killed. The English were forced to retreat. ("Our Captive Ancestors")

Once the captors and captives had crossed the Deerfield River, the English captives were told to remove their shoes and put on moccasins so they could walk through the snow more quickly. Some of the children were transported on sleighs or carried by their Indigenous captors.

Still, the conditions on the month-long trek were harsh. Of the 112 captives, it is estimated that 89 survived. The others either died along the way or were killed because they couldn't keep up. ("Our Captive Ancestors")

Meanwhile, Deerfield residents took efforts to repatriate their captured family members. Between late 1704 and 1707, Deerfield resident John Sheldon made three trips to New France to try to negotiate the return of the Deerfield captives. Edward Allen, Sarah's father, was part of the third delegation, which arrived in Montréal in August 1707. No documents exist to indicate whether Edward found his daughter, Sarah, who was living in Baie d’Urfé, about 20 miles from Montréal.

Of the 89 captives who survived the march to New France, 36 remained there permanently, including Sarah Allen, explains French Canadian genealogist Kim Kujawski. She states: "Most historians believe that those who stayed did so because they had formed community, family and religious bonds with those around them, and had become completely assimilated in their new surroundings."

According to the documentary My Name Is Sarah Allen, Guillaume Lalonde was living on a farm near the Quenet property in Baie d’Urfé and often went to see Sarah. Guillaume Lalonde was the son of Jean Lalonde and Marie Barbant (a fille du roi).

With the approval of Jean Quenet, Sarah married Guillaume on April 27, 1710, in Ste-Anne de Bellevue, under the name Marie Madeleine Hélène.

In May 1710, Sarah/Marie Madeleine was naturalized in New France, her name listed as "Madeleine Alleyn" in the naturalization document.

According to the documentary My Name Is Sarah Allen, after their marriage in 1710, Guillaume and Sarah/Marie Madeleine lived in Ste-Anne-de-Bellevue, where they had four children. In 1717, they moved to L'Île-Perrot, where they had six more children. In 1727, they moved to Les Cedres in the parish of Ste-Anne-de-Soulange, where they had four more children, for a total of 14 children. (Généalogie Québec identifies 12 children born to the couple, while several other sources indicate they had 13 children: 9 boys and 4 girls.)

Guillaume died on August 21, 1752, and was buried on August 22, 1752, in Les Cedres. Sarah/Marie Madeleine died on December 25, 1764, and was buried on December 26, 1764, in Les Cedres.

My connection to Sarah Allen and Guillaume Lalonde is as follows:

I would not have known of our family's connection to the incredible story of Sarah Allen if not for my sister. It's a fascinating tale of tragedy, survival and resilience.