Philospher
He is said to have been a Greek philospher before converting to Christianity; however, many scholars believe this is a confusion with two well-known Greek writers of his time, both named Hyginus.Church Hierarchy
The Liber Pontificalis claims that Hyginus organised the hierarchy within the church, although there are some disputes to this.Godparents
He is also claimed to have instituted the use of chrism in baptism, as well as ordering that all children have godparents to aid them in their catechumen, and to have established the dedicating of churches.Heresies
In his time, Gnosticism was increasing within the Roman church. This cult doctrine started within Judaism about a century before Christ, with many joining the Roman church during their 'adoption' to Christianity. Among many of their cultic beliefs, was that they did not believe in the "apostolic succession". Hyginus is believed to have excommunicated the Gnostic Cerdo, then re-admitting him after confessing his errors, only to be excommuncated again later for going back. Eventually they would all be excommunicated and later, the church would hunt them down and kill them.117-138: Roman Emperor, Hadrian
138-161: Roman Emperor, Antoninus Pius