The Big King sandwich is one of the major hamburger products sold by the international fast-food restaurant chain Burger King, and has been part of its menu for more than twenty years. During its testing phase in 1996–1997, it was originally called the Double Supreme and was configured similarly to the McDonald's Big Mac—including a three piece roll. It was later reformulated as a more standard double burger during the latter part of product testing in 1997. It was given its current name when the product was formally introduced in September 1997, but maintained the more conventional double cheeseburger format. Its introduction capped a period of sales success for Burger King, when the company successfully took on its rival McDonald's.