Heroes on Horseback takes a new look at a topic that will not go away: the charismatic leadership known as caudillismo that has characterized so much of South American history. Why were there so many Spanish American caudillos and so few in Brazil? Where did caudillos get their power? Answers emerge in John Charles Chasteen's account of the short careers of two back-country caudillos, Gumercindo and Aparicio Saravia, sons of a Brazilian immigrant family in northern Uruguay. Their story is set in the borderlands where Brazil and Spanish America met and mingled in the nineteenth century. Rather by accident, they became the last of the gaucho caudillos when, in the 1890s, they led hopeless revolts of mounted lancers against modern armies equipped with Mausers and Krupp artillery.