English: Red flag (banner) with Chi Rho attributed to the Byzantine (Eastern Roman) Empire can be used as an flag icon and replace a simple labarum made in black. The file can be used for the Byzantine Empire before the Palaiologos dynasty, but beware, the image is not a reconstruction of the authentic historical flag and is intended for practical purposes only. The Chi Rho symbol (☧) was first used by the Roman Emperor Constantine I (r. 306–337 AD) as part of a military standard (vexillum) known as the Labarum. The file contains elements of the black Simple Labarum and the shapes of the 14th century Byzantine imperial flag with same colors. Its shape coincides with the flag of the Empire of Trebizond and some military banners of the Ottoman Empire.