Although today not as frequent as many Acadian surnames in Louisiana, that of Theriot has a highly complex history, reflected in its widespread distribution in the southern part of the state. In Acadia the name was introduced by Jean Terriau, who arrived ca. 1637 with wife Perrine Bourg from the village of Martaizé, Loudun area, west-central France.* Comparatively few of his descendants came to Louisiana after the Expulsion of 1755. The earliest to arrive were two Theriot families, who by 1766 had settled along the Mississippi River in the first Acadian Coast (St. James Parish). One of the families included Françoise Melançon (widow of Joseph Thériot) and her four sons; the other was headed by a relative of Françoise's dead husband, another Joseph Terriot and his wife, Madeleine Bourgeois.

Both families left many descendants, some of whom stayed in the river parishes, but most settled elsewhere in southern Louisiana.

Among those who remained in St. James were three sons of Joseph Terriot and Madeleine Bourgeois: Pierre (m. 1789 Anastasie Michel), Joseph (m. 1797 Marguerite Berteau), and Jean-Baptiste (m. 1800 Marguerite Richard); a fourth son, Charles, moved to the Attakapas soon after he married Rosalie LeBlanc in 1804.

One of Pierre Terriot's sons, Pierre, Jr. (m. 1812 Marie-Séraphine Caillouet), established a large plantation near Convent, but soon after his death (ca. 1854) his heirs apparently sold the estate to Anglo planters.

Another son of Pierre, Sr., Michel-Éloi, as a young man of 24 left St. James for Bayou Lafourche, where in 1819 he married Séraphine Thibodeaux. The two settled at Lafourche Crossing below Thibodeauxville, but ca. 1839 Michel moved his large family into Terrebone Parish, forming the first sugar plantation ("St. Michel") along Bayou du Large near the present community of Theriot.

Most of Michel's nine sons and his many grandsons continued to live along the bayou and in the vicinity of Houma; after the Civil War his younger son Aurélien took over the family's plantation, which he managed until the end of the century.

Another son, however-Justinien (m. 1848 Meloe Lepine)-chose land near Raceland on the lower Lafourche for his home, where in antebellum days he operated a profitable plantation, an enterprise that declined after the Civil War.

The story of Widow Thériot's (Françoise Melançon) family and their descendants is even more complicated than that of Joseph Thériot and Madeleine Bourgeois.

Three of the widow's sons remained in St. James: Thomas (m. 1774 Marie Daigle), Ambroise (m. 1777 Madeleine Granger), and François-Xavier (m. ca. 1775 Geneviève Dupuis).

By 1788, however, son Paul (m.

ca. 1780 Françoise Guillot) had migrated to the Attakapas, making his home below St. Martinville.

Later, between 1795 and 1820 five of the widow's grandsons (sons of Thomas with Marie Daigle) all left St. James for the Attakapas, establishing the Theriot name from the La Pointe area near present Breaux Bridge to below New Iberia.

By the 1840s some of their descendants had moved to the northern part of Vermilion Parish near Abbeville, and as early as the 1870s some Theriots had penetrated the cheniers within the marshes of Cameron Parish.

To confuse the story further, in 1785 eight Theriot families, Acadian refugees who had been living in France, arrived in Louisiana.

Spanish authorities sent many of these to Bayou Lafourche.

There, one of the refugees, Jean-Charles (m. 1786 Madeleine Landry), having settled in Assumption Parish, established a long line of Theriots, most of whose members eventually migrated down-bayou to the Raceland-Lockport-Larose area, probably as farmers and fishermen; others settled near Houma and along Bayou Terrebonne as far as, and perhaps below, Montegut