The history of Rum is the history of sugar. One of those is the sugar cane (Saccharum officinarum), a tall, thick grass that has its origins in the islands of present-day Indonesia in the East Indies.
Chinese traders spread its cultivation to Asia and on to India. Arabs in turn brought it to the Middle East and North Africa where it came to the attention of Europeans during the Crusades in the 11th century.
In 1493 Christopher Columbus picked up cane cuttings from the Canaries while on his second voyage to the Americas and transplanted them to the island in the Caribbean that is now shared by Cuba, Haiti and the Dominican Republic. Portuguese explorers soon did like in Brazil.