In Grimms’ Fairy Tales there is a story called “The Stubborn Child” that is only one paragraph long. Here it is, in a translation by the fairy-tale scholar Jack Zipes:

Once upon a time there was a stubborn child who never did what his mother told him to do. The dear Lord, therefore, did not look kindly upon him, and let him become sick. No doctor could cure him and in a short time he lay on his deathbed. After he was lowered into his grave and covered over with earth, one of his little arms suddenly emerged and reached up into the air. They pushed it back down and covered the earth with fresh earth, but that did not help. The little arm kept popping out. So the child’s mother had to go to the grave herself and smack the little arm with a switch. After she had done that, the arm withdrew, and then, for the first time, the child had peace beneath the earth.

Jacob and Wilhelm Grimm were born to a prosperous couple (the father was a lawyer), Jacob in 1785, Wilhelm in 1786. The family lived in a big house in the Hessian village of Hanau, near Kassel, and the boys received a sound primary education at home. But when they were eleven and ten everything changed. Their father died, and the Grimms no longer had any money. With difficulty, the brothers managed to attend a good lyceum and then, as their father would have wished, law school. But soon afterward they began a different project, which culminated in their famous book “Nursery and Household Tales” (“Die Kinder- und Hausmärchen”), first published in two volumes, in 1812 and 1815, and now generally known as Grimms’ Fairy Tales.

The Grimms grew up in the febrile atmosphere of German Romanticism, which involved intense nationalism and, in support of that, a fascination with the supposedly deep, pre-rational culture of the German peasantry, the Volk. Young men fresh from reading Plutarch at university began sharing stories about what the troll said to the woodcutter, and publishing collections of these Märchen, as folk tales were called. That is the movement that the Grimms joined in their early twenties. They had political reasons, too—above all, Napoleon’s invasion of their beloved Hesse, and the installation of his brother Jérôme as the ruler of the Kingdom of Westphalia, a French vassal state. If ever there was a stimulus to German intellectuals’ belief in a German people that was culturally and racially one, and to the hope of a politically unified Germany, this was it.

Two things sustained the Grimms. First, their bond as brothers. For most of their lives, they worked in the same room, at facing desks. Biographers say that they had markedly different personalities—Jacob was difficult and introverted, Wilhelm easygoing—but this probably drew them closer. Wilhelm, when he was in his late thirties, made bold to get married, but the lady in question simply moved into the brothers’ house and, having known them for decades, made the domestic operations conform to their work schedule.

That was their other lodestar: their work. Eventually, their specialties diverged somewhat. Wilhelm remained faithful to folklore, and it was he who, after the second edition of “Household Tales” (1819), did all the editorial work on the later editions, the last of which was published in 1857. Jacob branched out into other areas of German history. Independently, Jacob wrote twenty-one books; Wilhelm, fourteen; the two men in collaboration, eight—a prodigious output. Though their most popular and enduring book was “Household Tales,” they were serious philologists, and, in the last decades of their lives, what they cared about most was their German Dictionary, a project on the scale of the Oxford English Dictionary. Wilhelm died at seventy-three. Jacob carried on for four years, and brought the dictionary up to “F.” Then he, too, died. Later scholars finished the book.