The sunburst flag's design is inspired by the Fianna of Irish mythology. Described as brave warriors who performed a large number of impressive feats,[who?] the Fianna referred to themselves as either Gal Gréine or Scal Ghréine, which both mean sunburst. The sunburst flag, and the symbol of the sunburst itself came into use by Irish nationalists during the 19th century. In 1858, the Irish Republican Brotherhood adopted the flag as their symbol. During the American Civil War, the sunburst motif was incorporated by several Irish regiments in their standards. In 1893 the Irish-language group called Conradh na Gaeilge established themselves, using the flag as the group's symbol in reference to the Fianna.