This chapter shows that the Grotton–St. Ange family was the most important political and military family in Upper Louisiana for the half century between 1720 and 1770. Louis St. Ange de Bellerive first came to prominence under the sponsorship of his father, Robert Grotton St. Ange. Shortly after Robert Grotton St. Ange's marriage to his second wife, Élisabeth Chorel, in 1718, the couple and Robert's two sons by his first wife, Pierre and Louis, headed west to establish the St. Anges as a leading family in the Illinois Country. This chapter traces the history of the Grotton–St. Ange family in the Illinois Country and looks at the expeditions of Étienne Veniard de Bourgmont, the first white man to ascend the Missouri River valley in 1714 and the one who built Fort d'Orléans. It also considers the presence of the St. Ange family at Fort d'Orléans, where Louis St. Ange de Bellerive replaced Robert Grotton St. Ange as commandant.