The Senyera, meaning "pennon", "standard", "banner", "ensign", or, more generically, "flag" in Catalan) is a vexillological symbol based on the coat of arms of the Crown of Aragon, which consists of four red stripes on a golden background. This coat of arms, often called bars of Aragon, or simply "the 4 bars" (les quatre barres), historically represented the king of the Crown of Aragon.
The senyera pattern is nowadays in the flag of four Spanish autonomous communities (Catalonia, Aragon, the Balearic Islands, Valencia), and is the flag of the historically Catalan-speaking city of Alghero in Sardinia. It is also used on the coat of arms of Spain, the coat of arms of Pyrénées-Orientales and of Provence-Alpes-Côte d'Azur, the flag of Roussillon and Provence in France, one quarter of the coat of arms of Andorra, and on the local flags of many municipalities belonging to these territories. The Senyera is also used more informally for the Catalan language.
It is also a synonym (in Catalan Senyal Reial or Senyera and old Spanish Señal Real or Señera) for Royal Flag, although the word normally refers to the Catalan and Aragonese flags. Also in Aragonese, it is usually referred to as O Sinyal d'Aragón, i.e. "The Sign of Aragón".