In Hoc Signo Vinces

The Latin phrase itself renders, rather loosely, the Greek phrase "ἐν τούτῳ νίκα", transliterated as "en toútōi níka" (Ancient Greek: [en túːtɔːi̯ níːkaː], Modern Greek: [en ˈduto ˈnika]), literally meaning "in this, conquer".

Lucius Caecilius Firmianus Lactantius was an early Christian author (c. 240 – c. 320) who became an advisor to the first Christian Roman emperor, Constantine I (and tutor to his son), guiding the Emperor's religious policy as it developed during his reign. His work De Mortibus Persecutorum has an apologetic character, but has been treated as a work of history by Christian writers. Here Lactantius preserves the story of Constantine's vision of the Chi Rho before his conversion to Christianity. The full text is found in only one manuscript, which bears the title, Lucii Caecilii liber ad Donatum Confessorem de Mortibus Persecutorum.

The bishop Eusebius of Caesaria, a historian, states that Constantine was marching with his army (Eusebius does not specify the actual location of the event, but it is clearly not in the camp at Rome), when he looked up to the sun and saw a cross of light above it, and with it the Greek words "(ἐν) τούτῳ νίκα" ("In this, conquer"), a phrase often rendered into Latin as in hoc signo vinces ("in this sign, you will conquer").

At first, Constantine did not know the meaning of the apparition, but on the following night, he had a dream in which Christ explained to him that he should use the sign of the cross against his enemies. Eusebius then continues to describe the Labarum, the military standard used by Constantine in his later wars against Licinius, showing the Chi-Rho sign. The accounts by Lactantius and Eusebius, though not entirely consistent, have been connected to the Battle of the Milvian Bridge (312 AD), merging into a popular notion of Constantine seeing the Chi-Rho sign on the evening before the battle.

The phrase appears prominently placed as a motto on a ribbon unfurled with a passion cross to its left, beneath a window over the Scala Regia, adjacent to the equestrian statue of Emperor Constantine, in the Vatican. Emperors and other monarchs, having paid respects to the Pope, descended the Scala Regia, and would observe the light shining down through the window, with the motto, reminiscent of Constantine's vision, and be reminded to follow the Cross.

 

The Kingdom of Portugal had used this motto since 1139, after the Miracle at the Battle of Ourique, when the first portuguese king D. Afonso Henriques, before his battle against the moorish King Ali ibn Yusuf, experienced a similar miracle to Constantine's. The miracle was later famously retold through the written epic poem the Lusíadas.

• Motto of the Portuguese Impire and monarchy ( When Jesus on the cross appeared to D.Afonso Henriques( first king of Portugal ) before the battle of Ouriques, gave him the portuguese symbol , the "Quinas", and said "In hoc signo vinces", since then it's on every Portuguese flag.)

• Inscribed on the banner of the Sanfedismo in 1799
• Inscribed in Greek on the flag (obverse side) of the Sacred Band of the Greek War of Independence
• Part of the trademark for Pall Mall cigarettes. "PALL MALL IN HOC SIGNO VINCES 'WHEREVER PARTICULAR PEOPLE CONGREGATE'"
• It is the public motto of the English Defence League, emblazoned around the group's logo.
• The phrase is the motto on some Byzantine coins (e.g. the folles of Constans II).
• It is the motto on most regimental flags of the Irish Brigade (France).
• In hoc signo vinces was the motto of the Sherbrooke Regiment, which is perpetuated by the Sherbrooke Hussars, a Canadian reserve regiment
• In hoc signo vinces is the motto on the O'Donnell coat of arms.
• It is the motto of the College of the Holy Cross in Worcester, Massachusetts.
• It is the official motto of the Knights Templar in the American York Rite of Freemasonry.
• It was the motto of the Ancient and Illustrious Order Knights Of Malta, a Protestant fraternal society
• It is the motto of the Regimiento de Caballería «Montesa» n.º 3 of the Spanish Army.
• It is the motto of the 2nd Battalion of the Norwegian Army
• It has been the public motto of Sigma Chi, a North American collegiate mens fraternity, since 1861.

• List of Latin phrases