St Radegund, a sixth-century royal ascetic who relinquished her position as the wife of a Frankish king and established a convent in Poitiers, is today a rather obscure French local saint. Yet in the nineteenth century, as a result of the tireless promotion of her cult by Édouard Pie, bishop of Poitiers from 1849 to 1880, St Radegund was widely invoked in France as ‘la sainte reine de la France’ and ‘la mère de la patrie’. Her wonder-working tomb, a popular devotional site in the Middle Ages, offered cures and Pie saw to it that the pilgrim trains to Lourdes made an obligatory prayer-stop at Poitiers. This article analyses devotion to St Radegund during the Second Empire and the Third Republic and explores some of the religious and political connotations of the cult of this royal saint. The development of the cult is particularly significant for it allows us to see, reflected on the local level, something of the larger struggle for national self-definition that was taking place in nineteenth-century French society as royalists contended with Bonapartists and republicans, clericals waged war against secularists and the ultramontanes sought to rouse their fellow countrymen in support of Pius IX.