 The exact age of the Swedish flag is not known, but the oldest recorded pictures of a blue cloth with a yellow cross date from the early 16th century, during the reign of King Gustav I.The first legal description of the flag was made in a royal warrant of 19 April 1562 as "yellow in a cross fashioned on blue".As stipulated in a royal warrant of 1569, the yellow cross was always to be borne on Swedish battle standards and banners.