<human>:  When did whaling start in the history of the world?
<bot>: Whaling started in the 15th century. It was a big business in the 18th century. In the 19th century, whales were hunted for their oil, which was used to make candles and lubricants. In the 20th century, whales were hunted for their meat. In the 21st century, whale hunting is now illegal.