Which island group was once called the Sandwich Islands?
When Captain James Cook arrived in Hawaii in 1778, the British explorer named the islands in honor of the Earl of Sandwich, John Montagu, who sponsored his exploration. (And, yes, , the beloved, edible sandwich was indeed also named after him.) The name stuck until the 1840s, when its local name, Hawaii, began to take prominence under local rule.
Source: History.info