Théodore Gentilz, painter, son of Pierre Louis Gentilz, Parisian manufacturer of custom-built carriages, was born in Paris in 1819. He was trained as draftsman, painter, and engineer at the Imperial School of Mathematics and Drawing, student of the painter Ramon Quesada Monvoisin and of "my master, [Eugène Emmanuel] Viollet-le-Duc." Gentilz was engaged in 1844 by the French entrepreneur Henri Castro to serve as surveyor, artist, and promotion agent for Castro's projected colony in Texas.
With John James, Charles DeMontel, and others, he laid out the village of Castroville and its satellites-Quihi, Vandenburg, New Fountain, and D'Hanis-known collectively as the Castro colony. During the ensuing years, he carried his painting gear and surveying instruments over far-flung trails from the western reaches of El Paso del Norte to the Gulf Coast and deep into Mexico.
In 1849, returning from one of his journeys to France on behalf of Castro, Gentilz brought back a French bride, Marie Fargeix-an accomplished musician-and his young sister Henriette. They settled in San Antonio, where, in 1852, Henriette married Gentilz's close friend Auguste Frétellière (author of "Reminiscences of a Castro Colonist, 1843–44"). Both families were active participants in the life of their Catholic parish, and Gentilz was a founding member of the French Mutual Relief Society, a fraternal and insurance organization.
Despite his friendships and intellectual life within the closed French circle, Gentilz focused his artistic vision on the indigenous cultures of the Southwest, whose long and rich history was yet to be recognized. Indians, Mexican ranchers and villagers, street scenes on both sides of the border, and Spanish missions all captured his attention. Typical of his paintings are the Camp of the Lipans, Comanche Chief, Sobre la Huella, Ranchero, Tamalero, Corrida de la Sandía, San Antonio, Fandango, San José de Aguayo, El Convite para el Baile, and Horse Racing at San Pedro Springs. In addition to his painting and surveying, for many years Gentilz taught painting at St. Mary's College and in his home (where Marie taught music). Two of his ablest students were Marie and Frétellière's daughter Louise, each of whom produced a small body of graceful paintings and drawings. At his death in San Antonio on January 4, 1906, he was survived only by his sister and her children.
Dedicated to history as well as to art, Gentilz tempered his somewhat rigid painterly style with considerable drafting skill to produce a valuable record of events, characters, customs, architecture, and landscapes of his place and time. As a historian he also attempted to recreate contemporary events to which he was not actually a witness, as in his Battle of the Alamo, Death of Dickinson, and Shooting of the 17 Decimated Texians at El Salado, Mexico. That which he deemed important to his period has proved important to posterity. Today his works, most of them in permanent collections (in the San Antonio Museum of Art and the Daughters of the Republic of Texas Library at the Alamo, for instance), are consulted by scholars and avidly sought by collectors.