Louis I, 1838–89, king of Portugal (1861–89), son of Maria II and Ferdinand II. He succeeded to the throne on the death of his brother Peter V. His reign was marked by much political turmoil and by a growth of republicanism, while a succession of alternating liberal and conservative ministries accomplished little. In 1886, Portugal secured French and German recognition of its claim to the African interior between Angola and Mozambique, but this was challenged by Great Britain. Slavery was abolished in the Portuguese colonies during Louis's reign, and Portugal made considerable progress in transportation, commerce, and industry. Louis was succeeded by his son, Charles I.