The conversion of Constantine is one of the most important events in ancient history. A Roman emperor, himself a god to the subjects of Rome, became the worshiper of a crucified provincial of his empire. Constantine favored the Christians throughput his reign. He surrounded himself with Christian bishops, freed the clergy from taxation, and spent large sums in building churches. One of his laws abolished the use of the cross as an instrument of punishment. Another enactment required that magistrates, city people, and artisans were to rest on Sunday. This was the first "Sunday law." [23] [Illustration: THE LABARUM The sacred military standard of the early Christian Roman emperors. First adopted by Constantine. It consisted of a staff or lance with a purple banner on a cross-bar. The two Greek letters XP (CHR) make a monogram of the word Christ (Greek _Christos_).] CHURCH COUNCIL AT NICAEA, 325 A.D. Significant of the emperor's attitude toward Christianity was his action in summoning all the bishops in the different provinces to a gathering at Nicaea in Asia Minor. It was the first general council of the Church. The principal work of the Council of Nicaea was the settlement of a great dispute which had arisen over the nature of Christ. Some theologians headed by Arius, a priest of Alexandria, maintained that Christ the Son, having been created by God the Father, was necessarily inferior to him Athanasius, another Alexandrian priest, opposed this view and held that Christ was not a created being, but was in all ways equal to God. The Council accepted the arguments of Athanasius, condemned Arius as a heretic, and framed the Nicene Creed, which is still the accepted summary of Christian doctrine. Though thrust out of the Church, Arianism lived to flourish anew among the Germanic tribes, of which the majority were converted to Christianity by Arian missionaries. [Illustration: ARCH OF CONSTANTINE Erected at Rome in 315 A.D. to commemorate the victory of Constantine over Maxentius. The monument consists of a central gateway and two smaller arches flanked by detached columns in the Corinthian style. The arch is decorated with four large statues in front of the upper story and also with numerous sculptures in relief.] CHRISTIANITY BECOMES THE STATE RELIGION UNDER THEODOSIUS, 379-395 A.D.