On the eve of Mexican independence one of the intellectual leaders of the movement, Dr. Servando Teresa José de Mier, whom the “new despotism” had incarcerated in the prison of San Juan de Ulúa, reflected on the Idea of the Constitution Conferred upon America by the Kings of Spain before the Invasion of the Old Despotism. He evoked with fervor the epoch—at the height of the reign of Charles V—when Fray Bartolome de Las Casas introduced the new laws protecting the Indians in the Council of the Indies (1542-1543), when he imposed upon the conquest the ideal of pacific evangelization formulated in his De unico vocationis modo, and in a memorable controversy finally triumphed over the “notorious Sepúlveda, advocate of war and slavery” (1550). “It was,” Mier maintained, “the most significant epoch of American history, for it marked the termination of America's major misfortunes and laid the foundation of her fundamental laws or true constitution.”