flag of a British crown possession, flown subordinate to the Union Jack (United Kingdom, flag of the), that consists of a white field (background) with a red Cross of St. George bearing a smaller yellow cross at its centre.

The English flag (England, flag of) (incorporating the Cross of St. George) was flown by the government of Guernsey for centuries. In the mid-19th century a Cross of St. George was displayed on a background of blue and white squares with the Union Jack in the canton. Several unofficial flags for Guernsey were adopted in the 20th century for use in sports events and other activities. During World War II, when German occupiers forbade the display of official British symbols on Guernsey, local vessels used the Cross of St. George flag.

The first official Guernsey flag was designed in the 1980s by Commander Bruce Nicolls, a retired Royal Navy officer. He drew his inspiration from the famous Bayeux Tapestry, an artifact documenting the Norman Invasion of England (AD 1066). On the tapestry is the flag with a yellow cross given to William the Conqueror by the pope. Nicolls represented this “Guernsey cross” in the centre of the red Cross of St. George to show that the islands had been part of the original duchy of Normandy before becoming a crown dependency of the English. The flag became official on May 9, 1985, commemorating the 40th anniversary of the liberation of Guernsey from German occupation. By adding the Bayeux Tapestry cross, Nicolls invented a distinctive design for Guernsey without infringing on the flag of England.