The diary of Heinrich Witt (1799-1892) is the most extensive private diary written in Latin America known to us today. Witt was born in Altona near Hamburg and went to Peru in 1824 for the English merchant house Gibbs. In his diary written in English, he describes his childhood and youth in Altona, his first professional years in England and his daily life and long voyages in Peru and to Europe. The diary gives a unique version of commerce and trade, politics and politicians, and of lawsuits and corruption in nineteenth-century Peru and abroad. It abounds in details about family life, customs and culture, and is a truly unique source for everyone interested in the history of Peru and of international trade and migration.