Labarum

The labarum (Greek: λάβαρον or λάβουρον^[2]) was a vexillum (military standard) that displayed the "Chi-Rho" symbol ☧, a christogram formed from the first two Greek letters of the word "Christ" (Greek: ΧΡΙΣΤΟΣ, or Χριστός) – Chi (χ) and Rho (ρ).^[3] It was first used by the Roman emperor Constantine the Great.^[4]

Ancient sources draw an unambiguous distinction between the two terms "labarum" and "Chi-Rho", even though later usage sometimes regards the two as synonyms. The name labarum was applied both to the original standard used by Constantine the Great and to the many standards produced in imitation of it in the Late Antique world, and subsequently.

^ A. Macgeorge, Flags, Glasgow (1881): The labarum of the emperors [...] frequently bore upon it a representation of the emperor, sometimes by himself and sometimes accompanied by the heads of members of his family."
^ Harry Thurston Peck, Harpers Dictionary of Classical Antiquities (1898), Labarum
^ In Unicode, the Chi-Rho symbol is encoded at U+2627 (☧), and for Coptic at U+2CE9 (⳩).
^ Chisholm, Hugh, ed. (1911). "Labarum" . Encyclopædia Britannica. Vol. 16 (11th ed.). Cambridge University Press. p. 2.

[1] A. Macgeorge, Flags, Glasgow (1881): The labarum of the emperors [...] frequently bore upon it a representation of the emperor, sometimes by himself and sometimes accompanied by the heads of members of his family."

[Harpers_Dictionary_of_Classical_Antiquities-2] Harry Thurston Peck, Harpers Dictionary of Classical Antiquities (1898), Labarum

[3] In Unicode, the Chi-Rho symbol is encoded at U+2627 (☧), and for Coptic at U+2CE9 (⳩).

[EB1911-4] Chisholm, Hugh, ed. (1911). "Labarum" . Encyclopædia Britannica. Vol. 16 (11th ed.). Cambridge University Press. p. 2.

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