 It found its final form in 1561, when he was working in the Colegio de San Gregorio.Originally planned as a six-volume work, each volume describes a decade of the history of the Indies from the arrival of Christopher Columbus in 1492 to 1520, and most of it is an eye-witness account.It was in the "History of the Indies" that Las Casas finally regretted his advocacy for African slavery, and included a sincere apology, writing, "I soon repented and judged myself guilty of ignorance.