The national flag of Spain (Spanish: Bandera de España), as it is defined in the Constitution of 1978, consists of three horizontal lines: red, yellow and red, the yellow stripe being twice the height of each red stripe. Traditionally, the middle stripe color was called by the archaic term gualda (weld, a natural dye); hence the flag's nickname la Rojigualda (the red–weld). The Cross of Burgundy is also known as "The Vane of Burgundy" or La Cruz de San Andrés as it is derived from St. In order to represent the King, they used to have another one, the "Coronela", during the reign of Charles I (Charles V as Holy Roman Emperor) that was made of yellow silk (the imperial color) with the embroidered imperial shield. This resulted in a common national symbol: colors derived from the Aragonese flag, a Castilian coat of arms, and the whole being Spanish.