The flag of the Seleucid Empire
The flag of the Seleucid Empire is, as can be seen, Seleucid purple with a strange symbol on it, in a different color of purple. The higher part of the symbol is a helm and the lower is an anchor. The founder of the Seleucid Empire was told by his mother that prior to his birth he was visited by Apollo who said she was pregnant with a future king. Apollo then gave his mother, Laodikea, a signet ring with an anchor.