Roman emperors Gratian, Valentinian II, and Theodosius I issue a new law against Christian heretics, with the Apollinarians being singled out in particular. As followers of the teachings of Apollinaris of Laodicea, the Apollinarians denied that Jesus could have a human mind like regular human beings. Jesus may have had a human body and soul, but his mind had to have been divine.
Apollinarism is thus a form of monophysitism, a heretical teaching that Jesus had just "one nature" (divine) instead of two natures, human and divine. It is thought that Apollinarism is an over-reaction to the Arian teaching that Jesus was not divine at all and it was condemned as a heresy in 381
According to the new Roman law:
"We command that the Apollinarians and all other followers of diverse heresies shall be prohibited from all places, from the walls of cities, from the congregation of honorable men, from the communion of the saints.
They shall not have the right to ordain clerics, they shall forfeit the privilege of assembling congregations either in public or private churches. No authority shall be granted to them for creating bishops; moreover, persons so appointed shall be deprived of the name bishop and shall forfeit the appellation of this dignity.
They shall go to places which will seclude them most effectively, as though by a wall, from human association.
Moreover, We subjoin to the foregoing provisions that to all the aforesaid persons the opportunity to approach and address Our Serenity shall be denied." [CTh 16.5.14]