Front side Constantine
Constantine I, born in Naissuss in 272 was a powerful Emperor who reigned over the Roman Empire until his death. He made the previously named city Byzantium (now Istanbul, Turkey) capital of the whole Roman Empire in 330 A.D. As emperor, he named the city Constantinople, which means "City of Constantine" in Greek.
Before Constantine became Emperor, he was fighting for the throne at the Battle of Milvian Bridge. When he saw a cross in the sky with the words in hoc signo vinces (Latin for "in this sign you shall conquer"), he changed his deity from Apollo to Jesus and won the battle. In pagan Rome before this, it had been against the law to believe in Christianity, and Christians had been tortured or killed, but Constantine made sure that this stopped, and that they were given their property back. During his reign, Constantine made Christianity the official religion of the Roman Empire. He went on to organize the whole Catholic Church at the Council of Nicea, even though he himself did not get baptized until near the end of his life.
Back side Constantine Arch, Edict of Milan
The Arch of Constantine is a triumphal arch in Rome, situated between the Colosseum and the Palatine Hill. It was erected to commemorate Constantine I's victory over Maxentius at the Battle of Milvian Bridge in 312. It is the latest of the extant triumphal arches in Rome.
The Constantine arch is 21 m high, 25.7 m wide and 7.4 m deep. The decoration of the arch heavily uses parts of older monuments, which are given a new meaning in the context of the Constantinian building. As it celebrates the victory of Constantine, the new "historic" friezes illustrating his campaign in Italy convey the central meaning: the praise of the emperor, both in battle and in his civilian duties. Other decoration is taken from the "golden times" of the Empire under Trajan, Hadrian and Marcus Aurelius places Constantine next to these "good emperors", and the content of the pieces evokes images of the victorious and pious ruler. Constantine legalized Christianity definitively in 313 as evidenced in the so-called Edict of Milan.

In hoc signo vinces - "By this sign you will conquer" and it is addressed to Constantine's vision before the Battle of Milvian Bridge. That sign from his vision is called Labarum, and is shown on the back of the banknote in the middle of the Constantie arch. Later on, Labarum was used as a military standard which displayed the first two Greek letters of the word Christ ( Greek: ΧΡΙΣΤΟΣ or Χριστός )—Chi (χ) and Rho, (ρ)