Pedro Montes was a wealthy 58-year-old Cuban businessman who bought four children, including three girls, who would become Amistad captives. On June 22, 1839 he obtained fraudulent passports authorizing the transport of his new slaves to his plantation at Puerto Principe on the northwest coast of Cuba. On June 28, at night in order to avoid British inspection, Montes departed Havana along with his slaves aboard the Amistad.

When the mutiny began aboard the Amistad, Montes attacked Cinque with a knife and stick. His attack was thwarted by Fanquanah, who slashed him with a sugar cane knife. Montes ran below deck and hid himself between two barrels, wrapped up in a sail. He was discovered by Fuleh, who intended to kill him until he was convinced by Kimbo that he might be useful in piloting the Amistad to Sierra Leone. Montes was taken on deck and tied to Ruiz. After Cinque held a knife to his throat, Montes agreed to sail east, but then tricked his captors by charting a westerly course at night.

After the Amistad's interception off Long Island, Montes began efforts to have the Africans, and the vessel and its cargo returned to him. As a practical matter, his legal interests were represented by U. S. Attorney Holabird.