The Danish Empire was a historical realm that included territories in Europe, North America, and the Caribbean, primarily during the 17th and 18th centuries. It was centered around the Kingdom of Denmark and included regions such as Norway, Iceland, and parts of Greenland. The empire was known for its maritime trade and colonial ventures, particularly in the West Indies. At its height, the Danish Empire also controlled Danish West Indies, which included islands like Saint Thomas, Saint John, and Saint Croix. The empire began to decline in the 19th century due to various conflicts and the loss of territories, ultimately leading to the sale of the Danish West Indies to the United States in 1917.